Exosomes in Cancer Research

Next generation sequencing has provided the ability to screen for novel microRNA (miRNA) biomarkers in biofluids of patients with cancer. Extravesicular vesicles in the peripheral blood, known as exosomes, provide a reliable source of miRNAs for disease biomarker detection. The molecular content of exosomes, readily available in body fluids such as blood, urine and saliva, is highly specific and a powerful biomedical tool. Exosomes generated during tumorigenesis and derived from cancer cells provide cancer fingerprints, detectable in peripheral blood. In addition, since cancer exosomes are messengers for signaling and alteration of the tumor microenvironment, it is no surprise that cancer features such as angiogenesis, chemoresistance and metastasis are associated with them, and their ability to facilitate the formation of a pre-metastatic niche as a primer for implantation of circulating tumor cells. The aim of this paper is to provide a review of the state-of-the-art of exosomes in cancer research, their role in cancer niche development with clinical correlation as biomarkers for cancer diagnosis and prognosis, as well as their future use in exo-therapy in the era of precision oncology medicine.