Droplet Digital PCR Analysis of Liquid Biopsy Samples Unveils the Diagnostic Role of hsa-miR-133a-3p and hsa-miR-375-3p in Oral Cancer
Department of General Surgery, Section of Maxillo Facial Surgery, Policlinico San Marco, University of Catania, 95123 Catania, Italy
Epidemiology Unit, IRCCS Istituto Nazionale Tumori “Fondazione G. Pascale”, 80131 Naples, Italy
Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
Otolaryngology Unit, Department of Medical Sciences, Surgical and Advanced Technologies, University of Catania, 95123 Catania, Italy
Research Center for Prevention, Diagnosis and Treatment of Cancer, University of Catania, 95123 Catania, Italy
Author to whom correspondence should be addressed.
These authors contributed equally to this work.
These authors share senior authorship.
Received: 12 October 2020 / Revised: 29 October 2020 / Accepted: 4 November 2020 / Published: 6 November 2020
Despite the availability of screening programs, oral cancer is often diagnosed due to the lack of effective biomarkers. Therefore, the identification of new effective diagnostic and late prognostic biomarkers is of fundamental importance for the management of this tumor type. In our previous computational study, we have identified a set of microRNAs (miRNAs) significantly dysregulated in oral cancer and with a potential diagnostic and prognostic significance for oral cancer patients. Starting from our preliminary bioinformatics results, the aim of the present study was to validate the diagnostic potential of four selected miRNAs, hsa-miR-133a-3p, hsa-miR-375-3p, hsa-miR-503-5p and hsa-miR-196a-5p, in liquid biopsy samples obtained from oral cancer patients and healthy donors. For this purpose, the expression levels of the selected miRNAs were determined in plasma samples by using specific miRNA probes and droplet digital PCR (ddPCR). The ddPCR results showed that the hsa-miR-133a-3p and hsa-miR-375-3p were significantly down-regulated in oral cancer and their evaluation in liquid biopsy samples can predict the risk of oral cancer development with high sensitivity and specificity. Finally, the computational analysis of miRNA expression and clinical-pathological features of patients allowed us to establish the functional role and prognostic significance of the two validated miRNAs.