Saliva samples to detect cancer, heart disease and diabetes?
Patients may one day spit into a cup instead of undergoing blood draws when being tested for the presence of cancer, heart disease or diabetes, say researchers in an article published online in the Journal of Proteome Research.
In a salivary proteome study, researchers at five institutions (The Scripps Research Institute; University of Rochester; University of Southern California; The University of California, San Francisco; and University of California Los Angeles) used the term "saliva" to mean salivary gland secretions, since an emerging theory states that the mix of proteins in salivary gland secretions tracks closely with that in blood, making saliva a potential diagnostic stand-in for blood.
Researchers led by Paul Denny, PhD, professor of Diagnostic Sciences, University of Southern California School of Dentistry, collected saliva from 23 adults of several races and both sexes. Although small, the sample was large enough to serve as a baseline list for near-future comparisons between healthy people and people with major diseases, researchers said.
By using mass spectrometry techniques, researchers identified 1,166 proteins in parotid and submandibular/sublingual saliva. They found that more than one-third of the saliva proteins also were found in the blood proteome. When they compared these proteins against known protein pathways and other proteomes, they had a first glimpse of the function of the core proteins.
They also found that a number of the salivary proteins matched proteins with known roles in Alzheimer, Huntington and Parkinson diseases; breast, colorectal and pancreatic cancer; and type 1 and 2 diabetes. Specifically, they found that a majority of the proteins were part of signaling pathways, which are central to the body's response to and, thus, diagnostic of systemwide diseases.
"Researchers have already shown that saliva proteins can be used to detect oral cancer and HIV infection," said coauthor Dr. Mireya González Begné, a research assistant professor of Dentistry in the Center for Oral Biology at the University of Rochester Medical Center. "We think this list will soon expand to include leading causes of death like cancer and heart disease, which, if caught early, are much more likely to be successfully treated."
The National Institutes of Health, National Institute of Dental and Craniofacial Research funded the study.
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