Abstract

Biology and Function of Exosomes in Cancer

Raghu Kalluri, RE Bob Smith Distinguished Chair in Cancer Research, Professor & Chairman, Department of Cancer Biology, MD Anderson Cancer Center

Humans circulate trillions of exosomes at all times. Exosomes are extracellular vesicles with a size range of 40-150 nm and a lipid bilayer membrane; and are released by all cell types. Normal exosomes contain DNA, RNA and proteins. Some proteins such as CD9, CD63 and flotillin are often detected on the surface of exosomes and serve as markers. Exosomes likely remove excess and/or unnecessary constituents from the cells, functioning like garbage bags. Although their precise physiological role remains largely unknown, is it suggested that exosomes may mediate specific cell-cell communication and activate signaling pathways in cells they fuse or interact with. Exosomes are detected in the tumor microenvironment and emerging evidence suggests that they play a role in facilitating tumorigenesis by regulating angiogenesis, immunity and metastasis. Circulating exosomes could be used as liquid biopsies and non-invasive biomarkers to potentially inform on early detection and diagnosis of cancer patients. Exosomes can be used for the treatment of cancer. This lecture will highlight some of the recent advances in the area of exosomes biology and their utility in the diagnosis and treatment of cancer. Additionally, the use of exosomes in personalized therapy for cancer patients will be discussed.