ABSTRACT
OBJECTIVES: Oral squamous cell carcinoma (OSCC) accounts for>90% oral cancer which is a leading cause of cancer death worldwide. Early diagnosis may well offer an opportunity to increase survival to this neoplasm. Micro(mi)RNA-interfered cancer progression is crucial, yet its migration machinery of OSCC is still unknown. To access whether the possible miRNA prognostic markers and underlying mechanisms, we developed a highly migratory TW2.6 MS-10 cells from TW2.6 cells to investigate the issue. MATERIALS AND METHODS: miRNA profiling was performed on TW2.6 and TW2.6 MS-10. Target miRNA was correlated to pathological status in OSCC patients by real-time RT-PCR. A downstream effector was identified using a bioinformatics analysis, and a 3'-untranslated region (UTR) reporter assay was used. RESULTS: An miRNA cluster, miR-17-92, including miR-17, miR-19b, miR-20a, and miR-92a, was found to be significantly down-regulated in TW2.6 MS-10 compared to TW2.6 cells. Overexpression of this cluster decreased the migratory ability of OSCC cell lines. We further demonstrated that miR-17 and miR-20a are the main miRNAs of miR-17-92 cluster which modulate OSCC migration. Clinically, miR-17/20a showed negative correlation with TNM stage and lymphatic metastasis. Through a bioinformatics screening analysis and 3'UTR reporter assay, we confirmed the integrin (ITG) ß8 as a direct target of miR-17/20a, and knockdown of ITGß8 reduced cell migratory capability of OSCC. CONCLUSIONS: miR-17/20a acts as a prognostic predictor of OSCC patients' outcome and a tumor migration suppressor miRNA.
