Proteomic profiling of vesicles released by 8701-bc cells

8701-BC cells were shown to release “membrane vesicles” playing a role in tumor progression mechanisms. On the other hand, production of “exosomes”, smaller vesicles known to be involved in immune response activation, had not been revealed. The first goal of this study was to separate different vesicle populations from 8701-BC cell conditioned medium. To this aim, the medium was differentially centrifuged. Western analysis revealed that the 15,000xg pelletted fraction contains β1-integrin, which had been shown to be clustered in membrane vesicles shed by 8701-BC cells, but not Hsc70, a protein found in exosomes. On the contrary, Hsc70 is detectable while β1-integrin is not present in the fr…