Low microRNA-622 expression predicts poor prognosis and is associated with ZEB2 in glioma

Background: MicroRNAs have been recently reported to play an important role in tumorigenesis and progression in several forms of tumors. Previous studies have shown that microRNA-622 (miR-622) was associated with glioma proliferation and invasion. However, the clinical significance of miR-622 in glioma has not been elucidated. The aim of our study was to investigate the clinical values of miR-622, as well as investigate the potential molecular mechanisms in glioma. Materials and methods: qRT-PCR and Western blot analysis were used to analyze the expression of miR-622 and ZEB2, respectively. Kaplan-Meier analysis and Cox's proportional hazards model were used in survival analysis. MTT assay, wound healing assay, transwell assay and flow cytometry analysis were carried out to detect the impact of miR-622 on glioma cell proliferation, migration, invasion and apoptosis. Results: Our result indicated that miR-622 expression was greatly decreased in glioma tissues and cell lines and the downregulation of miR-622 was significantly associated with the advanced pathological grade and low Karnofsky performance score of glioma. In addition, Kaplan-Meier curves with log-rank analysis revealed a close correlation between downregulation of miR-622 expression and low overall survival rate in glioma patients. Furthermore, Cox regression analysis demonstrated that downregulated miR-622 could be considered as an independent poor prognostic indicator in glioma patients. Finally, our findings demonstrated that miR-622 overexpression remarkably suppressed glioma cell proliferation, migration and invasion, while facilitated apoptosis by suppressing ZEB2 in vitro. Conclusion: Our study suggested that miR-622 may be identified as a valuable prognostic biomarker and a promising therapeutic target for glioma patients.