Salivary IL-6 mRNA is a Robust Biomarker in Oral Squamous Cell Carcinoma

• Published in: Journal of clinical medicine Vol. 8; no. 11; p. 1958
• Main Authors: Márton, Ildikó Judit, Horváth, József, Lábiscsák, Péter, Márkus, Bernadett, Dezső, Balázs, Szabó, Adrienn, Tar, Ildikó, Piffkó, József, Jakus, Petra, Barabás, József, Barabás, Péter, Olasz, Lajos, Kövér, Zsanett, Tőzsér, József, Sándor, János, Csősz, Éva, Scholtz, Beáta, Kiss, Csongor
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 13-11-2019
• Subjects: oral neoplasia; enzyme-linked immune-sorbent assay; ethanol consumption; smoking; periodontal disease/periodontitis; immunohistochemistry; salivary biomarkers; real-time quantitative PCR
• ISSN: 2077-0383; 2077-0383
• DOI: 10.3390/jcm8111958

Salivary IL-6 mRNA was previously identified as a promising biomarker of oral squamous cell carcinoma (OSCC). We performed a multi-center investigation covering all geographic areas of Hungary. Saliva from 95 patients with OSCC and 80 controls, all Caucasian, were collected together with demographic and clinicopathological data. Salivary IL-6 mRNA was quantified by real-time quantitative PCR. Salivary IL-6 protein concentration was measured by enzyme-linked immune-sorbent assay. IL-6 protein expression in tumor samples was investigated by immunohistochemistry. Normalized salivary IL-6 mRNA expression values were significantly higher (
< 0.001) in patients with OSCC (mean ± SE: 3.301 ± 0.885) vs. controls (mean ± SE: 0.037 ± 0.012). Differences remained significant regardless of tumor stage and grade. AUC of the ROC curve was 0.9379 (
< 0.001; 95% confidence interval: 0.8973-0.9795; sensitivity: 0.945; specificity: 0.819). Salivary IL-6 protein levels were significantly higher (
< 0.001) in patients (mean ± SE: 70.98 ± 14.06 pg/mL), than in controls (mean ± SE: 12.45 ± 3.29). Specificity and sensitivity of IL-6 protein were less favorable than that of IL-6 mRNA. Salivary IL-6 mRNA expression was significantly associated with age and dental status. IL-6 manifestation was detected in tumor cells and tumor-infiltrating leukocytes, suggesting the presence of a paracrine loop of stimulation. Salivary IL-6 mRNA is one of the best performing and clinically relevant biomarkers of OSCC.