Prostasomes (Exosomes) Mediate Functional Abilities to Recipient Cells through Transfer of Proteins and Nucleic Acids: A Comprehensive Model for Exosomal Intercellular Communication

The prostasome is the first described exosome and constitutes the third communication system between cells mediating messages besides gap junctions and soluble compounds such as hormones. Exosomes are nanometer vesicles surrounded by a lipid bilayered membrane and released by most cell types including malignant cells. The exosomal messenger system reaches distant cells even on the other side of the blood brain barrier. In this way they are able to interact with their target cells for delivery of their cargo. We here describe prostasomal properties in more detail thus exemplifying common exosomal characteristics. Myocardial derived exosomes (cardiosomes), are also described in order to highlight other common biological functions including damaged tissue, i.e. tissue repair. Abnormal tissue such as malignant progression can be driven by cancer cell derived exosomes, believed mainly to be mediated by different forms of short RNAs exerting their action through specific signaling pathways related to metastases, therapeutic resistance and immunosuppression.