miRNA-335 and miRNA-182 affect the occurrence of tongue squamous cell carcinoma by targeting survivin

The aim of the present study was to characterize the roles of two microRNAs (miRs) that have been reported to be differentially expressed in tongue squamous cell carcinoma (TSCC), miR-335 and miR-182. In total, 20 tumor tissue samples and 20 corresponding adjacent non-cancerous samples were collected from patients with TSCC to measure the expression of miR-335 and miR-182 and the potential shared target of these miRs, survivin, using reverse transcription-quantitative polymerase chain reaction and western blotting. In the TSCC tissue samples, significantly decreased expression of the two miRs and increased expression of survivin were detected compared with adjacent non-cancerous controls. Subsequently, it was confirmed that survivin was the target gene of miR-335 and miR-182 using a luciferase assay in TSCC cells. In order to examine the function of miR-335 and miR-182 in the development of TSCC, TSCC cells were transiently transfected with the mimics of the two miRs, and it was confirmed that the introduction of miR-335 and miR-182 to cells suppressed the expression of survivin and markedly inhibited the proliferation of the TSCC cells. Furthermore, miR-335 and miR-182 were found to induce cell cycle arrest by suppressing the expression of survivin. The present study revealed a negative regulatory role of miR-335 and miR-182 in the proliferation of TSCC cells by targeting survivin, and miR-335 and miR-182 may be novel therapeutic targets for the treatment of TSCC.