Diagnostic Accuracy of Salivary Gamma-synuclein in Oral Malignant and Premalignant Lesions

Synucleins are a family of small, highly conserved proteins found in vertebrates and are specially abundant in neurons particularly in presynaptic terminals (Surguchov et al., 2001). Gamma-synuclein is the third member of the synuclein family, and is predominantly found in the cytosol of tumor cells and functions both intra- and extra-cellularly. It is involved in the pathogenesis of different types of cancer and some neurodegenerative diseases (Liu et al., 2018). Smoking - a major risk factor for oral cancer and its progression - and nicotine-containing products were found to time-dependently up-regulate the Gamma-synuclein expression in cancer cells (Hsu et al., 2020a). Gamma-synuclein is released from tumor cells and was found to be elevated in tumors such as urinary bladder cancer (Liu et al., 2016), colorectal cancer, gastric adenocarcinomas and esophageal cancer (Liu et al., 2012). It is present in blood, serum, cerebrospinal fluid and saliva. The detection of extracellular synucleins in body fluids can reveal the first steps of the disease thus it can be used as a potential tool for early cancer detection (Surguchov, 2016). This study aims to identify the diagnostic accuracy of Gamma-synuclein in differentiating between oral malignant lesions and oral premalignant lesions.