Long noncoding RNAs (lncRNAs) play important roles in the initiation and progression of various cancers, including laryngeal squamous cell carcinoma (LSCC). Recently, lncRNA Sox2 overlapping transcript (SOX2-OT) has been identified as an oncogene in various cancers. However, the functional role and the regulatory mechanism of SOX2-OT in LSCC remains unclear. In this study, we found that SOX2-OT expression was increased and negatively correlated with PTEN expression in LSCC tissues. Furthermore, SOX2-OT overexpression promoted LSCC cell proliferation, migration, invasion, and suppressed cell apoptosis in vitro, as well as facilitated the in vivo tumorigenicity. By contrast, SOX2-OT silencing exerted the opposite effect. Mechanically, SOX2-OT interacted with EZH2 and recruited EZH2 to induce H3K27me3 and epigenetically inhibited PTEN expression in LSCC cells. Additionally, EZH2 silencing and PTEN overexpression significantly abrogated the SOX2-OT overexpression-mediated promotion of LSCC cell malignant behavior. Collectively, our findings demonstrate that SOX2-OT inhibits PTEN expression to facilitate LSCC development through EZH2-mediated H3K27me3. © 2019 IUBMB Life, 71(9):1230-1239, 2019.
Keywords: EZH2; H3K27me3; PTEN; SOX2-OT; laryngeal squamous cell carcinoma.
© 2019 International Union of Biochemistry and Molecular Biology.