Exosomes: messengers and mediators of tumor–stromal interactions

Intercellular communication is one of the most important factors involved in the maintenance of tissue homeostasis. The alteration of intercellular interaction correlates with a lot of human diseases including cancerogenesis. There are several types of such interconnection. First of all, it is a direct cell-cell contact, as it takes place in epithelium. The disturbance of this communication is expressed as a loss of cell-cell, cell-matrix contacts, disturbances of cell polarity etc. Another way of intercellular interaction involves mutual influence via paracrine factors produced by corresponding cells. However, there is another kind of information exchange between the cells, namely microvesicular transportation. It was revealed that the exosomes take part in intercellular communication in normal tissues as well as in malignant neoplasia. The present review provides the recent information on the formation of exosomes, their composition and especially the exosome participation in tumor-stromal interactions