Long noncoding RNA XIST increases the aggressiveness of laryngeal squamous cell carcinoma by regulating miR-124-3p/EZH2

Highlights: • Data from this study provides the first evidence that over expression of XIST promotes laryngeal squamous cell carcinomas. • XIST might be used as therapeutic target of LSCC. • XIST plays an important role in progression of LSCC. -- Abstract: The long non-coding RNAs (lncRNAs) are an emerging class of cancer regulators. The objective of the study was to elucidate the roles and underlying mechanisms of XIST in laryngeal squamous cell carcinoma. Quantitative real-time PCR (qRT-PCR) suggested that XIST was highly upregulated in laryngeal squamous cancerous (LSCC) tissues. Knockdown of XIST, mediated by lentiviral transfection of XIST-specific short-hairpin RNA (shRNA), led to the inhibition of proliferation, migration, and invasion of LSCC cells in vitro. In vivo, XIST knockdown also suppressed the growth of LSCC xenografts in mice. Upregulation of miR-124 and downregulation of EZH2 were concomitantly observed after XIST knockdown, and our data suggested that XIST served as the competitive endogenous RNA of miR-124 to modulate EZH2 expression. Moreover, ectopic overexpression of EZH2 prominently attenuated the anti-proliferation activity by XIST knockdown. Therefore, XIST plays an important role in progression of LSCC by modulating the miR-124-EZH2 axis.