Fig 1.
Study design.
Table 1.
List of examined salivary protein biomarkers for OSCC in different countries.
The proteins included in the studies carried out in different countries are indicated. The proteins in bold were found to be potential biomarkers for OSCC. The abbreviations of protein names are used according to gene name.
Table 2.
Patient data.
Fig 2.
Salivary cytokine levels determined with Luminex-based multiplex assay.
The concentration (pg/ml) of the studied cytokines is indicated in case of control (CTRL) and OSCC group. Below each graph the p value is indicated.
Table 3.
Optimized SRM parameters used for the mass spectrometric examination of salivary proteins.
The Q1 and Q3 m/z values, the type of “y” ion used, the dwell time, declustering potential (DP) and collision energy (CE) is indicated in case of each studied peptide.
Fig 3.
Quantitative analysis of salivary proteins by SRM.
The log2 fold change in case of thioredoxin, S100A9, profilin and catalase is shown. The comparison between the (A) age matched controls (MC) and healthy controls (HC), (B) OSCC group and healthy control (HC) group, (C) OSCC group and age matched (MC) group and (D) OSCC group and both healthy and matched control groups is indicated. * indicates significant change, p<0.05.
Table 4.
Results of mixed-effect variance analysis of OSCC and MC group differences.
The log2 fold change (logFC) standard error (SE), T values (Tvalue) and the FDR corrected p-values are shown.
Fig 4.
Estimation of predictive power of possible biomarkers using ROC curve analysis.
The sensitivity (y axis) was plotted versus 1−specificity (x axis) in case of each potential biomarker alone or in combinations. The area under the curve is indicated on each pane. The sensitivity and specificity was calculated for each biomarkers and biomarker combination.
Fig 5.
Salivary protein levels determined with ELISA.
The salivary concentration of (A) thioredoxin, (B) S100A9 protein and (C) IL-6 is indicated in case of young healthy controls (YC), age matched controls (MC) and OSCC group. In cases where significant difference was observed the p value is indicated. (D) ROC analysis of the combined effect of IL-6 and S100A9 protein.