Suppressed expression of long non-coding RNA HOTAIR inhibits proliferation and tumourigenicity of renal carcinoma cells.

Although long non-coding RNAs (lncRNAs) are known to play an important role in cell regulation in several cancers, the regulatory mechanisms in renal carcinoma cells remain unclear. HOX transcript antisense RNA (HOTAIR), an lncRNA, coordinates with chromatin-modifying enzymes to regulate gene silencing. HOTAIR is over-expressed in several types of carcinoma cells. Thus, we hypothesised that lncRNA HOTAIR is crucial for cell proliferation and invasion and that its knockdown induces apoptosis in renal carcinoma cells. lncRNA HOTAIR expression was found to be elevated in renal carcinoma cells. Additionally, lncRNA HOTAIR knockdown by RNA interference with siRNA was found to significantly affect the cell cycle in the G0/G1 phase and weaken the abilities of cell proliferation and invasion in vitro. Xenograft experiments confirmed that the growth of xenograft tumours formed by renal carcinoma cells was suppressed after silencing lncRNA HOTAIR expression. Moreover, chromatin immunoprecipitation (ChIP) and RNA-binding protein immunoprecipitation (RIP) assays revealed that knockdown of lncRNA HOTAIR led to the weakening of the recruitment and binding abilities of EZH2 and H3K27me3 locus with lncRNA HOTAIR. Furthermore, the cell cycle-related gene locus was in an active transcriptional state by the silencing of lncRNA HOTAIR expression and modulation of covalent histones.