Objective To investigate the effects of microRNA-519b-3p (miR-519b-3p) on laryngeal carcinoma Hep-2 cell growth,and to analyze the underlying molecular mechanisms.Methods The effects of miR-519b-3p on the growth and cell cycle of Hep-2 cells transfected with miR-519b-3p mimic were tested by MTT assay and flow cytometry,respectively.The mRNA and protein expressions of the related genes were tested by reverse transcription polymerase chain reaction (RT-PCR) and Western blot,respectively.The expressions of miR-519b-3p were tested by real-time RT-PCR in 48 pairs of laryngeal carcinoma and adjacent tissue samples.Results The expression of miR-519b-3p in laryngeal carcinoma tissues was significant lower than that in adjacent non-cancerous tissues (SAct =2.989,t =2.693,P ＜ 0.01).Increasing the level of miR-519b-3p inhibited significantly Hep-2 cell proliferation,arrested the cell cycle in the G2/M phase (10.29％ ± 4.63％,t =4.395,P ＜ O.05),and decreased significantly the percentage of cells in the S phase (7.56％-± 2.05％,t =3.555,P ＜ O.05),with the increase in the expression of cyclin dependent kinase (CDK) 1 and the decrease in the expressions of CDK 2 and Cyclin A.RT-PCR and Western blot showed that miR-519b-3p down-regulated the protein but not mRNA expressions of HuR and cyclooxgenase-2 (COX-2) genes.Conclusions The expression of MiR-519b-3p as carcinoma suppressor gene is low in laryngeal carcinoma.The cell cycle of Hep-2 cells was arrested in the G2/M phase by MiR-519b-3p.