This identification requires techniques based on differential and gradient high speed centrifugations, find more immunoelectronmicroscopy, purity assessments by Western blotting and detection of canonical markers by flow cytometry of exosomes. These first steps are fundamental not only to exclude contaminations derived from other cell compartments but also to assess the presence of bona fide exosomes, based on recent findings and standard protocols existing for exosome handling. Nowadays, technical advances in this field and agreements on the definition of exosomes reached by the scientific community, allow distinction of

this kind of organelle from others, this website giving investigators the opportunity to study “state-of-the-art” exosomes. As a ten-years experienced group investigating tumor exosomes, we believe that although many secrets of these fascinating

vesicles have been disclosed, there are as many still untold. Apparently, we are at the beginning of a long way to go, but, as outlined in this review, observed features and effects mediated by tumor exosomes start to merge into a single, albeit multifaceted claim. In fact, to cite some examples, the elimination of activated T cells by pro-apoptotic molecules together with immunosuppressive effects transmitted by TGFβ containing tumor exosomes are recurrent findings of different groups working on distinct cancer histologies, underlining the importance of these achievements. In conclusion we would like to point to the enormous potential of tumor exosomes as mediators of immunosuppression and disease progression

in cancer patients. Dissection Adenosine of the pathways leading to these pro-tumorigenic features will greatly enhance our understanding in this context offering at the same time a great opportunity for the identification of new targets for cancer therapies. The authors declare that there are no conflicts of interest. The authors’ work was supported by grants from the Italian Association for Cancer Research (AIRC, Milan), the Ministry of Health (Rome) and German Research Foundation (DFG, Forschungsstipendium GZ: BU2677/1-1). “
“Ever since metastasis has been investigated, models and concepts about how the metastatic disease process works have been suggested [1]. These have provided a framework within which to understand clinical observations and experimental findings, have served as an important tool for directing further research, and have suggested how new therapies that address metastatic disease might be developed. Most early concepts were based on clinical observations and autopsy findings.