Neuropilin-1 is a glial cell line-derived neurotrophic factor receptor in glioblastoma

Abstract

The aim of this study was to identify the receptor for glial cell line-derived neurotrophic factor (GDNF) in glioblastoma multiforme (GBM). After GST pull-down assays, membrane proteins purified from C6 rat glioma cells were subjected to liquid chromatography-tandem mass spectrometry (LC-MS/MS). The differentially expressed proteins were annotated using Gene Ontology, and neuropilin-1 (NRP1) was identified as the putative GDNF receptor in glioma. NRP1 was more highly expressed in human GBM brains and C6 rat glioma cells than in normal human brains or primary rat astrocytes. Immunofluorescence staining showed that NRP1 was recruited to the membrane by GDNF, and NRP1 co-immunoprecipitated with GDNF. Using the NRP1 and GDNF protein structures to assess molecular docking in the ZDOCK server and visualization with the PyMOL Molecular Graphics System revealed 8 H-bonds and stable positive and negative electrostatic interactions between NRP1 and GDNF. RNAi knockdown of NRP1 reduced proliferation of C6 glioma cells when stimulated with GDNF. NRP1 was an independent risk factor for both survival and recurrence in GBM patients. High NRP1 mRNA expression correlated with shorter OS and DFS (OS: χ2=4.6720, P=0.0307; DFS: χ2=11.013, P=0.0009). NRP1 is thus a GDNF receptor in glioma cells and a potential therapeutic target.

Glial Cell Line-Derived Neurotrophic Factor (GDNF) Promotes Angiogenesis through the Demethylation of the Fibromodulin (FMOD) Promoter in Glioblastoma

“…Previous studies have shown that the expression of GDNF in human glioblastoma is significantly increased compared to normal brain tissues [ 9 , 21 ]. Additionally, it has been reported that GDNF participates in regulating the proliferation, migration, and invasion of glioblastoma cells [ 9 , 10 , 22 , 23 ]. It is also well known that VEGF plays an important role in neovascularization in brain tumors [ 24 ].…”

Doublecortin undergo nucleocytoplasmic transport via the RanGTPase signaling to promote glioma progression

“…Cytoplasmic and nuclear protein extraction reagents (Beyotime) with PMSF were used for the extraction of nuclear and cytoplasmic fractionations as described by the manufacturer. For co-Immunoprecipitation, lysates were extracted with IP buffer and carried out as previously described [31].…”

“…Post-translational modifications such as phosphorylation may modulate nuclear import rates, e.g., phosphorylation of adjacent Ser111/112 N-terminal to the NLS of SV40T antigen greatly enhances its nuclear import [41]. We had previously reported that GDNF contributes to glioma progression [2,31], while GDNF has also been linked to the activation of kinases in favor of glioma [42]. We asked if GDNF can promote DCX phosphorylation and subsequently affect nuclear import.…”

Semaphorin 3C and Its Receptors in Cancer and Cancer Stem-Like Cells

“…As Sema3C signaling has been implicated in GSC maintenance, we will focus our discussion on its receptors in glioblastoma. Elevated Nrp1 expression is a risk factor for glioblastoma recurrence and shorter patient survival [ 75 ]. Disruption of Nrp1 signaling by siRNA knockdown significantly inhibits proliferation of glioma cell lines [ 76 ] phenocopying Sema3C knockdown.…”