Saliva is a mirror of the body. The ability to utilize saliva to monitor the health or disease status of an individual is a highly desirable goal for healthcare and biomedical research. As an accessible bodily fluid that can be obtained without invasive methods it fulfills the requirements of the ideal diagnostic medium.

The translational research group focuses on the identification of biomarker signature patterns in saliva indicative of local and systemic health status using genome-wide screening technologies, in particular with regards to early detection of disease.

Transcriptomics

The identification of human interleukin 8 mRNA and protein in saliva as potential markers of oral cavity and pharyngeal cancer in our laboratory led to the hypothesis that constituent human mRNAs are present in saliva. To utilize the full diagnostic potential of saliva, one needs to decipher and catalogue its informative components such as the salivary transcriptome, comprehensively.

We were the first to successfully isolate RNA from cell-free saliva supernatant in quantities proven to be sufficient for use in RT-PCR, q-PCR, and microarray experiments.

Our initial report on the salivary transcriptome demonstrated that it consists of at least 3000 mRNAs. Of these 3000 mRNAs, 180 are common between different healthy subjects, constituting the socalled “normal salivary transcriptome core” (NSTC).

To demonstrate the diagnostic and translation potential of the salivary transcriptome, we have profiled and analyzed saliva from head and neck cancer patients. Based on 4 genes from the NSTC (IL8, OAZ1, SAT, and IL1B) we were able to discriminate and predict if a saliva sample was from a cancer or control subject, with a combined sensitivity and specificity of 94%. Currently, we are aiming to identify RNA biomarkers in saliva of patients with other cancers or autoimmune diseases.

Technology Development

Our group has established an important collaboration with the UCLA school of Engineering and a biotech partner to develop biosensors for real-time, ultrasensitive, and ultraspecific detection of salivary diagnostic analytes.

The ultimate goal is to develop a portable device that analyses biosensor data obtained from a whole saliva sample and which can be used in any doctors or dentists practice. The overall concept is revolutionary and, when successful, will change the current paradigm of disease diagnostics.

Publications

1. Li Y, Denny P, Ho CM, Montemagno C, Shi W, Qi F, Wu B, Wolinsky L, Wong DT. The Oral Fluid MEMS/NEMS Chip (OFMNC): diagnostic and translational applications. Adv Dent Res. 2005 Jun;18(1):3-5.

2. Li Y, St John MA, Zhou X, Kim Y, Sinha U, Jordan RC, Eisele D, Abemayor E, Elashoff D, Park NH, Wong DT. Salivary transcriptome diagnostics for oral cancer detection. Clin Cancer Res. 2004 Dec 15;10(24):8442-50.

3. St John MA, Li Y, Zhou X, Denny P, Ho CM, Montemagno C, Shi W, Qi F, Wu B, Sinha U, Jordan R, Wolinsky L, Park NH, Liu H, Abemayor E, Wong DT.    Interleukin 6 and interleukin 8 as potential biomarkers for oral cavity and oropharyngeal squamous cell carcinoma. Arch Otolaryngol Head Neck Surg. 2004 Aug;130(8):929-35.

4. Li Y, Zhou X, St John MA, Wong DT. RNA profiling of cell-free saliva using microarray technology. J Dent Res. 2004 Mar;83(3):199-203.