Enhanced miR-9 promotes laryngocarcinoma cell survival via down-regulating PTEN.

MicroRNAs (miRNAs) play important roles in gene regulation during laryngocarcinoma. MiR-9 is a potential oncomiR, but its function in laryngocarcinoma is not known. The aim of this study is to investigate the roles of miR-9 in laryngocarcinoma. We found miR-9 expression was higher in laryngocarcinoma tissues compared with their normal controls, so did the laryngocarcinoma cells. Cellular function of miR-9 indicated that miR-9 restoration in laryngocarcinoma cells could promote cell proliferation and metastasis. Phosphatase and tensin homolog (PTEN) was predicted as a target gene of miR-9 and verified using luciferase reporter assay. PTEN expression was down-regulated in the laryngocarcinoma cells with miR-9 overexpression. We also found that miR-9 expression was negatively associated with PTEN expression in laryngocarcinoma tissues.