miRNA-124-3p/neuropilin-1(NRP-1) axis plays an important role in mediating glioblastoma growth and angiogenesis.

Glioblastoma multiforme (GBM) is the most lethal brain malignancy which involves multi-gene abnormality. Unfortunately, effective therapy against GBM remains lacking. Previously, we found that NRP-1 and its downstream NRP-1/GIPC1 pathway played an important role in GBM. In our study, we further investigated the upstream signaling of NRP-1 to understand how it is regulated. First, we identified that hsa-miR-124-3p was miRNA differentially expressed in GBM and in normal brain tissues by high-throughput sequencing. Then, by dual luciferase reporter gene, we found miR-124-3p can specially bind to the 3'UTR region of the NRP-1 thus suppresses its expression. Moreover, miR-124-3p overexpression significantly inhibited GBM cell proliferation, migration and tumor angiogenesis which resulted in GBM apoptosis and cell cycle arrest, putatively via NRP-1 mediated PI3K/Akt/NFκB pathways activation in GBM cells. Meanwhile, miR-124-3p overexpression also suppressed tumor growth and reduced tumor angiogenesis when targeted by NRP-1 in a PDX model. Furthermore, NRP-1 mAb exerted synergistic inhibitory effects with miR-124-3p overexpression in GBM. Thus, we discovered that miR-124-3p acts as the upstream suppressor of NRP-1 which promotes GBM cell development and growth by PI3K/Akt/NFκB pathway. The miR-124-3p/NRP-1/GIPC1 pathway as a new pathway has a vital role in GBM, and it could be considered as the potential target for malignant gliomas in future.