Potential of Cancer Cell Derived Exosomes in Clinical Application: A Review of Recent Research Advances

Background: Exosomes are 30- to 100-nm, membrane-bound vesicles that are released by most types of cells, including tumor cells. Exosomes contain a great variety of bioactive molecules, including signal peptides, microRNA, lipids, and DNA. In cancer, tumor cells aberrantly secrete large quantities of exosomes to transport paracrine signals or to contribute to tumor environment interaction at a distance. Objective: The goal of this review was to discuss the recent advances on the mechanism of cancer-derived exosomes in tumor regulation. Methods: Pertinent articles and abstracts were identified through searches of PubMed for literature published from 1983 to December 2013. Search terms included exosome, tumor, cancer, diagnosis, and therapy. Results: All of the exposed evidence points to communication between cancer cells and their surroundings, either mediated by cancer cell derived exosomes or by stromal cell derived exosomes. This communication probably supports tumor proliferation, motility, invasion, angiogenesis, and premeta-static niche preparation. In addition, recent research implies that cancer cell derived exosomes play a suppressive role in cancer-directed immune response. Conclusions: The biomarkers detected in bodily fluid derived exosomes imply a potential for exosomes in cancer diagnosis. Also, exosomes could be used as a vehicle to selectively deliver therapeutic nucleic-acid drugs or conventional drugs for tumor therapy. The tolerability and feasibility. of cancer exosomes in diagnosis and therapy need to be further evaluated. (C) 2014 Elsevier HS Journals, Inc. All rights reserved.