Downregulation of miR-383 promotes glioma cell invasion by targeting insulin-like growth factor 1 receptor.

Invasiveness is a major clinical feature of glioma, an aggressive brain tumor with poor prognosis. Although there is emerging evidence that some microRNAs are involved in the glioma cell invasion process, it remains necessary to find functional microRNAs and elucidate the underlying molecular mechanisms. Here, we reported that a microRNA, miR-383, was downregulated in gliomas and inversely correlated with glioma pathological grades. Downregulation of miR-383 enhanced, whereas upregulation of miR-383 inhibited, the glioma cell invasive ability. Furthermore, we found that downregulation of miR-383 activated the AKT signaling following upregulation of MMP2 expression by directly targeting insulin-like growth factor 1 receptor (IGF1R). Importantly, we demonstrated that IGF1R expression is critical for miR-383 downregulation-induced cell invasion. Taken together, these findings uncover a novel regulatory mechanism for constitutive IGF1R signaling activation in glioma cancer and may provide miR-383 as a useful diagnostic marker or therapeutic target.