Functional studies of tunneling nanotube-dependent cell-to-cell communication by high-throughput screening approaches

Intercellular communication is a major requirement for the development and maintenance of multicellular organisms. In the case of animals diverse mechanisms for the exchange of signals between cells have been established during evolution, including the se cretion of molecules as well as communication through gap junctions. Recently, we discovered thin membrane channels, which can be formed de novo between animal cells resulting in the formation of complex cellular networks. These channels, referred to as t unneling nanotubes (TNTs), mediate membrane continuity between connected cells. Furthermore, they have been shown to facilitate the intercellular transfer of organelles, cytoplasmic signaling molecules and membrane components. We here propose to analyze t he proteins transferred between established mammalian cell lines via TNTs by a proteomic approach. In addition, we will perform an siRNA screen to specifically interfere with the TNT-dependent communication system. The best candidates will be tested for t heir capability to inhibit a possible TNT-dependent intercellular transfer of the human estrogen receptor alpha, an important protein with central importance for breast cancer development and treatment. We believe that our study will increase the current knowledge on the structure/function of TNTs and will provide tools to selectively interfere with the TNT-mediated transfer of cellular components that may be used for the development of new therapeutical agents against e.g. cancer.