MicroRNA-urile salivare ca biomarkeri pentru malignitatea orală

Abstract

Background. Saliva sampling is a non-invasive, cheap, easy-to-access alternative to traditional tissue and blood sampling. Saliva is an accurate indicator of bodily conditions, and salivary biomarkers may serve as early diagnostic tools. In this study we aimed to validate the salivary expression of a panel of 5 microRNAs, identified from a literature screen as potential noninvasive biomarkers for oral squamous cell carcinoma (OSCC) diagnosis, prediction and therapy monitoring. Materials and methods. The research subjects included patients diagnosed with oral squamous cell carcinoma hospitalized at the Clinic of Oral & Maxillofacial Surgery in Timisoara. The biological samples (saliva) were collected from the patients before the biopsy procedure. We included in this study a group of 4 patients and a control group of 4 individuals without OSCC. For microRNA quantification, we performed reverse transcription using the TaqMan® MicroRNA Reverse Transcription Kit (Thermofisher) followed by quantitative Real-Time PCR (qRTPCR) using TaqMan™ MicroRNA Assays (Thermofisher); all qRT-PCR reactions were performed in triplicate. Results. With the exception of miR-181b, all the investigated microRNAs were found to have deregulated expression in OSCC patients’ saliva. Hsa-miR-137 was found to be up-regulated in the saliva of OSCC patients while hsa-miR-205 was found to be strongly down-regulated. However, we were able to confirm the activation of expression of hsa-miR-127-5b and the strong repression of hsa-miR-375 in the saliva of OSCC patients. The data upon hsa-miR-181 expression in OSCC have been conflicting, ranging from strong down-regulation in tissue samples and possible usage as therapeutic tool to correlation with metastasis propensity; however, we have not detected changes in the expression levels in saliva. Conclusions. Detection of deregulated miRNA biomarkers in saliva samples is a promising noninvasive assay for risk assessment of oral malignancy, which may add value to the histologic diagnosis.