Role of stem cell-derived exosomes in cancer.

Exosomes are small, extracellular membrane- enclosed vesicles that contain a variety of molecules, including proteins, DNA, mRNA and non-coding RNA; these vesicles have been defined as new tools for intercellular communication between cells. Numerous types of cells, including stem cells, secrete exosomes into the extracellular environment, and are significant communicators in the tumor microenvironment. Stem cells are a unique cell population defined by their ability to indefinitely self-renew, differentiate into a variety of cell lines, and form clonal cell populations.