Functional importance of exosome in cancer development

Abstract

The tumor microenvironment is a complex tissue comprising variable numbers of tumor cells, epithelial cells that originated cancer cells, fibroblasts, endothelial cells, and infiltrating leucocytes. Cell-cell communication of cancer cells and microenvironmental cells are critical for the acquisition of malignancy in human cancer. It has been shown how cytokines can control cancer cell-mediated phenotypic changes in the cellular microenvironment. Cytokines are considered key molecules for controlling autocrine or paracrine communications within and between individual cell types. Although the secretion of humoral factors from cancer cells to microenvironmental cells is essential for metastasis during cancer development, the precise molecular mechanisms of cell-cell communications of cancer cells and microenvironmental cells remain unclear. Recent reports highlight that the small membrane vesicle, exosome, which contains various types of proteins, mRNA, non-coding RNA and miRNAs, is novel player in cell-cell communication. In the last few years, it has become clear that exosome play critical roles in mediating cell-cell communication, specifically among immune cells, endothelial cells, fibroblasts and cancer cells. These findings provide evidences that components in exosome are required for cell-cell communication in various physiological and pathological conditions. In this review, we will introduce recent research on the contribution of components in exosome in cancer metastasis and the application of exosome in diagnosis and therapy against cancer development.