Extracellular vesicles as a platform for ‘liquid biopsy’ in glioblastoma patients

Abstract

Extracellular vesicles (EVs) are cell-secreted vesicles that range from 30–2000 nm in size. These vesicles are secreted by both normal and neoplastic cells. Physiologically, EVs serve multiple critical biologic functions, including cellular remodeling, intracellular communication, modulation of the tumor microenvironment and regulation of immune function. Because EVs contain genetic and proteomic contents that reflect the cell of origin, it is possible to detect tumor-specific material in EVs secreted by cancer cells. Importantly, EVs secreted by cancer cells transgress anatomic compartments and can be detected in the blood, cerebrospinal fluid, and other biofluids of cancer patients. In this context, there is a growing interest in analyzing EVs from the biofluid of cancer patients as a means of disease diagnosis and therapeutic monitoring. In this article, we review the development of EVs as a diagnostic platform for the most common form of brain cancer, glioblastoma, discuss potential clinical translational opportunities and identify the central challenges associated with future clinical applications.

Keywords::

• biomarker
• exosomes
• extracellular vesicle
• glioma
• microvesicle

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Diagnosis and therapeutic monitoring remains a major challenge for neuro-oncologic diseases, such as glioblastomas.

• Extracellular vesicles (EVs) are cell-secreted vesicles that are 30–2000 nm in size. EVs contain genetic and proteomic contents that reflect the cell of origin.

• Glioblastoma cells secrete EVs that harbor tumor-specific mRNAs, miRNAs and proteins. These EVs transgress multiple anatomic compartments and can be detected in the blood and cerebrospinal fluid of glioblastoma patients.

• Pilot studies have demonstrated that glioblastoma disease burden and therapeutic responses associate with protein, miRNA and mRNA profiles of EVs isolated from the biofluids of glioblastoma patients.

• Optimization and validation of results provided by the pilot studies are needed to advance EV as a platform for glioblastoma biomarker development.

Notes