Long noncoding RNA NEAT1 regulates radio-sensitivity via microRNA-27b-3p in gastric cancer.

backgroundLong noncoding RNA nuclear-enriched abundant transcript 1 (NEAT1) exhibits an oncogenic role in multiple cancers, including gastric cancer (GC). But, the functions of NEAT1 in modulating radio-sensitivity of GC and its potential molecular mechanisms have not been totally elucidated.

methodsqRT-PCR was performed to detect the expressions of NEAT1 and microRNA-27b-3p (miR-27b-3p). Kaplan-Meier survival curves for NEAT1 expression in GC created using KM Plotter. Colony formation assay was used to determine the survival fraction. Cell apoptosis was evaluated by flow cytometry. Luciferase reporter assay was used to verify the relationship between miR-27b-3p and NEAT1.

resultsNEAT1 was highly expressed while miR-27b-3p was downregulated in GC tissues and cells. NEAT1 was negatively correlated with that of miR-27b-3p and associated with poor overall survival. Moreover, NEAT1 and miR-27b-3p varied inversely after radiation in GC tissues and cells. Loss of NEAT1 or upregulation of miR-27b-3p increased the effect of radiation on cell survival fraction inhibition and apoptosis promotion. In addition, NEAT1 negatively regulated the expression of miR-27b-3p in GC cells. Interestingly, the depletion of miR-27b-3p dramatically attenuated the NEAT1 knockdown-mediated function in AGS and MKN-45 cells treated with radiation in vitro. Similarly, downregulation of NEAT1 enhanced the radiation-mediated inhibition of tumor growth, which was mitigated by decrease of miR-27b-3p.

conclusionNEAT1 depletion enhanced radio-sensitivity of GC by negatively regulating miR-27b-3p in vitro and in vivo.