Decreased miRNA-637 is an unfavorable prognosis marker and promotes glioma cell growth, migration and invasion via direct targeting Akt1

Although increasing evidence indicated that the deregulation of microRNAs (miRNAs) contributes to tumorigenesis and invasion, little is known about the role of miR-637 in human gliomas. In the present study, we found that the expression level of miR-637 was significantly reduced in clinical glioma tissues compared with normal brain tissues. Moreover, we revealed that the introduction of miR-637 dramatically suppressed glioma cell growth, migration and invasion in vitro and in vivo. Further studies revealed that Akt1 is a direct target gene of miR-637. Silencing of Akt1 inhibited the growth and invasion of glioma cells by decreasing phosphorylated Akt, beta-catenin, phosphorylated Foxo1 and Cyclin D1 and inducing the expression of Foxo1, which was consistent with the effect of miR-637 overexpression. Suppressed expression of miR-637 and increased Akt1 protein levels were correlated with unfavorable progression and poor prognosis, respectively, and a negative relationship between the miR-637 expression and Akt1 protein levels was observed in gliomas. Our findings provide new insights into the role of miR-637 in the development of gliomas, and implicate the potential application of miR-637 in cancer therapy.