Gather round the spittoon, partners, there’s a new Ome in town. The miRome has joined the proteome and transcriptome as the “third diagnostic alphabet in saliva,” extols UCLA dental prof David Wong.
For the past seven years or so the NIH (in particular the National Institute of Dental and CranioFacial Research) has been pushing saliva as an emerging biofluid — as a complement to blood, urine, and CSF. And with miRNA also emerging as a diagnostic constituent, Wong and his colleagues decided it was high time to look to the salivary miRome for differences between diseased and healthy individuals.
They found what they were looking for. In the first instance of miRNA from saliva being used as a cancer diagnostic, Wong’s group discovered that oral squamous cell carcinoma patients had significantly reduced levels of miR-200a and miR-125a in both whole saliva and salivary supernatant (don’t ask).
The study – initially conducted a few years ago, but just now published – is a proof of concept that salivary miRNA can be used for rapid, non-invasive diagnostics. “We wanted to start with something that is local and proximal to the fluid,” Wong says.
“We and other groups are working on not only oral diseases, but exploring the potential of saliva being reflective of systemic disease as well.” Can the salivary miRome – along with the proteome and transcriptome — reveal if there’s an early onset of lung cancer or pancreatic cancer?
“My prediction is that these miRNA signatures will be in saliva as well.” But, Wong warns, don’t count on them being the same signatures found in other bodily fluids. “That really constitutes the effort of why we really have to take this discovery initiative in saliva. We just can’t count on the fact that we find these things in blood and say, well, me too, I can find these things in saliva.” And as if that wasn’t enough, Wong says that they’ve just had a paper accepted on the salivary metabolome as well.
Read about the “hidden treasures and hidden secrets in saliva” in Clinical Cancer Research, September 2009