Salivary transcriptomics and biomarkers of oral squamous cell carcinoma

Saliva is rich in DNA, RNA, proteins, microorganisms and metabolites, containing large amounts of bio-information, similar to blood, and reflecting the physiological or pathological state of the whole body. Additionally, with its advantages of non-invasive collection methods, safe transport and low transportation cost, saliva has attracted extensive attention of scholars recently as a potential substitute for blood. With the rapid development of high-throughput techniques such as microarray technology, whole genome sequencing and whole transcriptome sequencing, a variety of disease-specific salivary biomarkers have been discovered. Salivary transcriptomics, a bridge connecting genomics and proteomics, provides a comprehensive understanding of gene transcription, RNA composition and interactions. This methodology not only allows the investigation of salivary components with temporal and spatial specificity but also reveals regulatory networks during disease development, with high potential for the early screening and assessment of diseases. Here, we outline the development of salivary transcriptomics, highlight its current research status in oral cancer from two aspects of technological and clinical applications, and further address prospects and challenges of the near future.