Tumor-derived exosomes are increasingly recognized as important players in cell-cell communication and have been implicated in cancer initiation and stimulate invasive behavior of cancer cells leading to metastasis. However, insight into the regulatory control of exosome release dynamics hampers direct demonstration on their actions in vitro and in vivo. We developed methods that can visualize exosome release from living cancer cells. Live total internal fluorescence (TIRF)-microscopy can demonstrate that tumor microenvironment (TME) components released by tumor stroma cells activate signaling pathways that in turn seem to promote fusion of intracellular compartments with the plasma membrane resulting in exosomes release. This knowledge will be exploited to discover novel drug targets.
.Figure: Projection of exosome release events (yellow spots) in a cervical cancer cell (blue) over a time-course of 3 minutes.