Background: Squamous Cell Carcinoma (SCC) includes more than 90% of malignancies
of the oral cavity. Early diagnosis could effectively improve patients' quality of life and treatment
outcomes of oral cancers. MicroRNAs as non-encoding genes have great potential to initiate
or suppress cancer progression. Recent studies have shown that disruption of micro-RNA regulation
is a common occurrence in cancers.
Objective: This study set out to evaluate the expression of microRNA-15a (miR-15a) and microRNA-
16-1 (miR-16-1) in the saliva of Oral Squamous Cell Carcinoma (OSCC) patients in comparison
with a healthy control group.
Methods: This case-control study was performed on fifteen patients with OSCC and fifteen healthy
volunteers as the control group. A 5 ml of non-stimulating whole saliva was collected by spitting
method from patients and controls and stored at -70°C. The expression of miR-15a and miR-16-1
was investigated using quantitative Reverse-Transcription Polymerase Chain Reaction (RT-qPCR).
Results: MiR-15a and miR-16-1 were downregulated in OSCC patients compared with the control
group (p<0.001). The sensitivity of miR-15a and miR-16-1 in differentiating OSCC patients from
healthy individuals was 93.3% and 86.67%, respectively, and their specificity was 86.67% and
92.33%, respectively. The diagnostic accuracy of miR-15a was 90%, and miR-16-1 was 93.3%.
Conclusion: The present study showed a decrease in the relative expression of miR-15a and
miR-16-1 in OSCC patients compared with healthy individuals. It is probable to introduce salivary
values of miR-15a and miR-16-1 as a non-invasive tool for early detection of OSCC. Decreased expression
of miR-15a and miR-16-1 in OSCC indicates the possible effective role of these genes in