Discovery and pre-validation of salivary extracellular microRNA biomarkers panel for the non-invasive detection of benign and malignant parotid gland tumors
Menée sur des échantillons de salive prélevés sur des patients atteints d'une tumeur de la glande parotide (38 tumeurs malignes, 29 tumeurs bénignes), cette étude identifie une signature qui, basée sur l'expression de 4 micro-ARNs, pourrait être utile pour le diagnostic de la maladie
Purpose: This study is to explore differences in salivary microRNA (miRNA) profiles between patients with malignant or benign parotid gland tumors as a potential pre-operative diagnostic tool of tumors in the salivary glands.
Experimental Design: Whole saliva samples from patients with malignant (n=38) or benign (n=29) parotid gland tumors were obtained from the Salivary Gland Tumor Biorepository (SGTB). After total RNA isolation, human miRNA cards were used for miRNA-profiling. The differential miRNA expression was analyzed using 2-sided Wilcoxon test. Real Time-quantitative PCR (RT-qPCR) was used to validate selected miRNAs in an independent sample set. Receiver-operating-characteristics (ROC) curve and probability of malignancy was exploited to evaluate the diagnostic power of the validated miRNAs.
Results: With miRNA-profiling, 57 of 750 investigated miRNAs were differently expressed, of which 54 showed higher miRNA expression in samples from patients with malignant tumors than those from patients with benign tumors. Validating the expression in an independent sample set of 9 miRNAs revealed indeed higher expression of miRNAs in malignant samples compared to benign samples. The expression of 6 validated miRNAs was statistically significantly different between the two groups (P <0.05). A 4-miRNA-combination was able to discriminate between saliva samples from patients with malignant tumors from those of patients with benign parotid gland tumors (sensitivity 69%, specificity 95%).
Conclusions: Salivary miRNA profiles differ in saliva from patients with malignant from saliva from patients with a benign parotid gland tumor. These preliminary results are promising to develop a non-invasive diagnostic tool for diagnosing tumors in the salivary glands.
Clinical Cancer Research , résumé, 2013