Mesenchymal Stem Cell Derived Exosomes in Cancer Progression, Metastasis and Drug Delivery: A Comprehensive Review

With the development of cancer treatments, it has become a popular research focus that mesenchymal stem (or stromal) cells (MSCs) have the functional mechanisms that influence cancer progression. One of the underestimated mechanisms is secretion of highly specialized double-membrane structures called exosomes. Mesenchymal stem cells generate several exosomes that may act as paracrine mediators by exchanging genetic information. MSC-derived exosomes are microvesicles ranging from approximately 60-200 nm in size and detected in various body fluids. It has been demonstrated that MSC-derived exosomes are involved in tumor growth, angiogenesis, metastasis, and invasion. Furthermore, emerging evidence suggests that as natural nanocarriers, MSC-exosomes are responsible for multidrug resistance mechanisms, reverse effect of radiation injury, and immune regulation, which can be used in clinical applications for cancer therapy. The present review aims to briefly describe the properties and biological functions of MSC-exosomes in cancer progression and its possible clinical applications in the future.