In-situ monitoring calcium signaling through tumor microtubes for single cell-cell communication via an open microfluidic probe

Cell-to-cell communication at a single cell resolution level is essential for the regulation of cell metastasis and invasion. In this work, an open microfluidic probe was established to investigate a dynamic calcium signal transmission between single cell via tumor microtubes (TMs) structure connected. Compared with traditional single cell-cell communication, the open microfluidic probe could provide a single cell stimulation with lower cellular damage via an injection-aspiration laminar flow in-situ, avoiding a complicated process for the capture of single cell pairs. Meanwhile, the open microfluidic probe enabled a different stimulation environment for the target cell pair to record a dynamic signal transmission, rather than a balanced result with same microenvironment. On such a single cell stimulation platform, the heterogeneity of depolarization response in glioma cells was explored. An obvious signal transmission between TM-connected cell pairs could also be observed after a single cell stimulation. Subsequently, an opposite-direction motion in TM-connected cell pairs was recorded, which tends to be ignored at the cell population level. And the degree of cell depolarization would be positive correlation with the tumor motion. These results could indicate such an open microfluidic probe could provide a new perspective for single cell analysis and the opposite-direction motion in TM-connected cell pairs could be applied in the future investigation on the tumor metastasis and invasion mechanism.