Abstract

Liquid Gold in Precision Medicine: Exploiting Extracellular Vesicles as Biomarkers to Diagnose and Monitor Cancer

Andrew Godwin, Professor and Division Director, Genomic Diagnostics, Founding Director, Kansas Institute for Precision Medicine, Deputy Director, KU Cancer Center, University of Kansas Medical Center

Pathologic analysis of tumor tissue biopsies is the gold standard for the initial diagnosis of cancer. However, recently liquid biopsies, which analyze tumor-derived material circulating in the bloodstream and other bodily fluids, are rapidly gaining traction in the clinic. These tests offer considerable potential in oncology, which include early detection, monitoring treatment response and disease recurrence. Liquid biopsy biomarkers include circulating tumor cells, cell-free DNA, nanoparticles, and extracellular vesicles (EVs). Regarding the latter, EVs are showing great promise as circulating biomarkers. The International Society for Extracellular Vesicles define EVs as particles naturally released from the cell that are delimited by “a lipid bilayer and cannot replicate”. Central among EVs are nano-sized vesicles (ranging from 40 to 150 nm in diameter) of endocytic origin also known as small EVs/exosomes, which are produced and released by most cell types under normal physiologic and in diseased states. sEVs carry cargo representative of their originating cell including nucleic acids, cytokines, membrane-bound receptors, and a wide assortment of other, biologically active lipids and proteins. Since sEVs travel systemically throughout the body, efforts are underway to exploit them as potential biomarkers to detect and monitor disease states. Ways to exploit sEVs for cancer diagnostics and monitoring response to therapy will be discussed.