Low expression of lncRNA MEG3 promotes the progression of oral squamous cell carcinoma by targeting miR-21.

Abstract

The aim of this study was to explore whether maternally expressed gene 3 (MEG3) could facilitate the proliferation and migration of oral squamous cell carcinoma (OSCC) cells by selectively binding to miR-21, thereby participating in the progression of OSCC. The expression levels of MEG3 and miR-21 in OSCC tissues and normal control tissues were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The effects of MEG3 and miR-21 on cell proliferation and migration were examined by cell counting kit-8 (CCK-8), transwell, and scratch assay, respectively. Meanwhile, cell cycle was detected using flow cytometry. The binding relationship between miR-21 and MEG3 was confirmed by dual luciferase assay. In addition, MEG3 and miR-21 were simultaneously knock-down to figure out whether MEG3 could regulate the proliferation and migration of OSCC cells through targeted binding to miR-21. QRT-PCR results indicated that MEG3 expression in OSCC tissues was remarkably lower than that of normal control tissues. However, the expression of miR-21 was significantly higher in OSCC tissues. Meanwhile, it was found that inhibiting MEG3 expression in OSCC cell lines could significantly promote cell proliferation and migration, while the simultaneous inhibition of miR-21 showed the opposite effect. Dual Luciferase assay results revealed that MEG3 could selectively bind to miR-21. In addition, we demonstrated that the knockdown of MEG3 in Tca-8113 and CAL-27 cells partially reversed the inhibitory effect of downregulated-miR-21 on cell proliferation and migration. These results further suggested that MEG3 might regulate OSCC cell proliferation via selectively binding to miR-21. Low expression of MEG3 can promote the proliferation and migration of OSCC cells through targeted binding to miR-21.