Our studies demonstrated that tumour exosomes are a major tumour-derived factor that acts systemically to promote bone marrow-derived cells (BMDCs) recruitment to the tumour and metastatic microenvironments (Peinado et al., Nature Med., 2012).
Our recent results together with Drs. Lyden and Bromberg demonstrate that tumour-derived exosomes are uptaken by organ-specific cells preparing the pre-metastatic niche. Exosome proteomics revealed distinct integrin expression depending on their specific organ of metastasis.
Therefore, we postulate that exosome integrins could serve as a ‘ZIP’ code for exosomes to home in metastatic organs triggering local effects reinforcing organ-specific metastasis. Our clinical data indicate that the profiling of integrins in circulating exosomes could be used to predict organ-specific metastasis (Hoshino et al. Nature, 2015).