Saliva diagnostics – Current views and directions

Abstract

The purpose of this mini-review is to make an update about the present and future applications of saliva as a diagnostic biofluid in many fields of science such as dentistry, medicine and pharmacotherapy. Using saliva as a fluid for diagnostic purposes would be a huge breakthrough for both patients and healthcare providers since saliva collection is easy, non-invasive and inexpensive. We will go through the current main diagnostic applications of saliva, and provide a highlight on the emerging, newly developing technologies and tools for cancer screening, detection and monitoring. AbstractIn this review, we provide an update on the current and future applications of saliva for diagnostic purposes. There are many advantages of using saliva as a biofluid. Its collection is fast, easy, inexpensive, and non-invasive. In addition, saliva, as a ''mirror of the body,'' can reflect the physiological and pathological state of the body. Therefore, it serves as a diagnostic and monitoring tool in many fields of science such as medicine, dentistry, and pharmacotherapy. Introduced in 2008, the term ''Salivaomics'' aimed to highlight the rapid development of knowledge about various ''omics'' constituents of saliva, including: proteome, transcriptome, micro-RNA, metabolome, and microbiome. In the last few years, researchers have developed new technologies and validated a wide range of salivary biomarkers that will soon make the use of saliva a clinical reality. However, a great need still exists for convenient and accurate point-of-care devices that can serve as a non-invasive diagnostic tool. In addition, there is an urgent need to decipher the scientific rationale and mechanisms that convey systemic diseases to saliva. Another promising technology called liquid biopsy enables detection of circulating tumor cells (CTCs) and fragments of tumor DNA in saliva, thus enabling non-invasive early detection of various cancers. The newly developed technology-electric field-induced release and measurement (EFIRM) provides near perfect detection of actionable mutations in lung cancer patients. These recent advances widened the salivary diagnostic approach from the oral cavity to the whole physiological system, and thus point towards a promising future of salivary diagnostics for personalized individual medicine applications including clinical decisions and post-treatment outcome predictions.

Feasibility of the salivary transcriptome as a novel biomarker in determining disease susceptibility

“…Although the prospect of a gene expression profile of saliva with the identification of biomarkers for periodontitis susceptibility is novel, further work is currently ongoing as the main method of identification of salivary transcriptomic using microarray and validation by means of the quantitative real‐time PCR is being enhanced. For example a new high‐resolution array from Affymetrix, GeneChip Human Transcriptome Array 2.0 (HTA 2.0) is capable of detecting all transcriptome including >6 million probes targeting coding transcripts, exon‐exon splice junctions and non‐coding transcripts . The recent development platform of transcriptomic analysis is by using next‐generation sequencing (RNA‐Seq), which has multiple advantages over hybridization or the sequence‐based approach .…”

Functionalized Biomimetic Magnetic Nanoparticles as Effective Nanocarriers for Targeted Chemotherapy

“…In this scenario ligands such as monoclonal antibodies (mAbs) or their fragments and growth factors, which specifically bind to biomarkers overexpressed on tumor cells, are grafted on the BMNPs. Most of these biomarkers are surface receptors for growth factors such as folic acid, transferrin, and tyrosine kinase receptors . In particular, Met is the tyrosine kinase receptor of hepatocyte growth factor (HGF receptor) that is overexpressed on many types of cancers (see http://www.vai.org/met).…”

Salivary Colony Stimulating Factor‐1 and Interleukin‐34 in Periodontal Disease

“…Saliva has potential to reflect local and systemic status through presence of inflammatory and immune components related to pathogenesis and diagnosis 4 , 5 . Salivary interleukin (IL)‐1β and matrix metalloproteinase (MMP)‐8 increase in periodontitis, and levels restore after treatment 6–8 .…”