Is Salivary Exosome the Answer to Early Detection of Oral Cancer?

Abstract

The presence of exosomes in almost all bodily fluids including saliva1 represents a promising
surrogate approach to investigate tumour markers. This has important clinical implications for
developing non-invasive salivary diagnostics and therapeutics.2 Human saliva is an ideal fluid for
developing non-invasive diagnostics and salivary biomarkers have been demonstrated in clinical
studies showing promising diagnostic potentials but lacking in sensitivity mostly due to complexity
of saliva.2,3 Hence, this led to the emerging interests on exosomes which are membrane-bound extracellular
vesicles carrying specific membrane proteins with numerous types of nucleic acids4 and
protein cargos,2,5,6 well protected from degradation by extracellular enzymes. Their size (50-150 nm
diameter) is an advantage for purification and reducing the overall complexity of saliva.2 Most of the
salivary exosome studies to date have been restricted to characterization of normal healthy samples.2
Emerging studies began looking at biochemical properties of disease-derived saliva exosomes.2,5,6
So, it seems no brainer that salivary exosome serves as the perfect target for finding a biomarker that
could enable early oral cancer detection by means of a simple saliva test.