Long non-coding RNA HOTAIR promotes tumor cell invasion and metastasis by recruiting EZH2 and repressing E-cadherin in oral squamous cell carcinoma.

HOX transcript antisense RNA (HOTAIR), a long intergenic non-coding RNA (lncRNA), functions as a molecular scaffold to link and target the histone modification complexes PRC2 and LSD1, then reprograms chromatin states by coupling histone H3K27 methylation and H3K4 demethylation for epigenetic gene silencing to promote cancer metastasis. It is associated with poor survival in several solid cancers. In this study, we show that HOTAIR expression increased in oral squamous cell carcinoma (OSCC) compared with non-tumor tissue and is associated with metastasis, the stage and histological differentiation. In addition, overexpression of HOTAIR indicated poor overall survival (OS) and disease-free survival (DFS) in OSCC patients. Knockdown of HOTAIR by siRNA in OSCC cells decreased cell proliferation and colony formation, increased cell invasion and migration, and induced apoptosis in vitro. Furthermore, significant negative correlation between HOTAIR levels and E-cadherin levels was found in OSCC tissues and cell lines, and HOTAIR contributed to the regulation of E-cadherin through binding to EZH2 and H3K27me3 with the E-cadherin promoter. Our findings suggest that HOTAIR expression is associated with OSCC and may be one of critical targets in progression and metastasis, and an indicator of poor survival in OSCC.