Exosomes as Biomarkers Show Potential in Recent Review

The reported diameter of exosomes is between 30 and 100 nanometers, which is larger than low-density lipoproteins but much smaller than red blood cells. Exosomes, which contain RNA, proteins, lipids, and metabolites that are reflective of the cell type of origin, are either released from the cell when multivesicular bodies fuse with the plasma membrane, or they are released directly from the plasma membrane. Exosomes have specialized functions and play a key role in coagulation, intercellular signaling, and waste management. Consequently, there is a growing interest in the clinical applications of exosomes for prognosis, therapy, and as biomarkers for health and disease.

Investigators at Swansea University (United Kingdom) and colleagues at the International Iberian Nanotechnology Laboratory (Braga, Portugal) reviewed recent advances in the exploitation of exosomes for diagnostic and therapeutic applications in the July 2017 issue of the journal Trends in Molecular Medicine. They also discussed various facets of nanoparticles, namely the isolation and manipulation of exosomes, the construction of synthetic exosome-like particles in vivo, and their potential use in the treatment of various diseases.

Exosome diagnostics, although available, remain unapproved by regulatory agencies. On the other hand, the reviewers reported that exosome approaches to therapeutic interventions are far-reaching - from packaging of therapeutic agents to driving immune responses. Potential applications range from oncology to regenerative medicine, and commercial GMP production at therapeutically relevant quantities is already underway. One of the most useful properties of exosomes is that they are able to cross barriers such as the plasma membrane of cells, or the blood/brain barrier. This makes them well suited for the targeted delivery of therapeutic molecules.

Citing one example, the reviewers pointed out that exosomes can trigger positive and negative immunomodulatory effects, as observed in early exosome clinical trials for advanced non-small cell lung cancer, thus potentially impacting on disease progression.

First author Dr. Steve Conlan, professor of molecular and cell biology at Swansea University, said, "Our survey of research into exosomes shows clearly that they offer enormous potential as a basis for detecting and treating disease. Further studies are necessary to turn this research into clinical outcomes, but researchers and funders should be very encouraged by our findings. Our own research in Swansea is investigating the use of exosomes and exosome-like synthetic nanoparticles in combatting ovarian and endometrial cancer."

Related Links:
Swansea University
International Iberian Nanotechnology Laboratory