Endosome associated trafficking regulator 1 promotes tumor growth and invasion of glioblastoma multiforme via inhibiting TNF signaling pathway.

Purpose: Endosome associated trafficking regulator 1 (ENTR1) is a novel endosomal protein, which can affect multiple cellular biological behavior by remodeling plasma membrane structures. However, little is known regarding its function and underlying mechanisms in glioblastoma multiforme.

Methods: Expression profile and clinical signature were obtained from The Public Database of human tumor. Immunohistochemical staining and western blotting assays were used to measure ENTR1 expression level. Human primary GBM tumor cells and human GBM cell lines A172, U87 and U251 were used to clarify the precise role of ENTR1. CCK-8 assays, wound healing and transwell invasion assays were designed to investigate cell viability, invasion and migration of GBM cells, respectively. Underlying molecular mechanisms of ENTR1 were determined via RNA-seq analysis. Tumor formation assay was used to validate the influence of ENTR1 in vivo.

Results: Compared with normal brain tissues, ENTR1 was highly expressed in gliomas and correlated with malignant grades of gliomas and poor overall survival time. The proliferation and invasion of GBM cells could be weaken and the sensitivity to temozolomide (TMZ) chemotherapy increased after knocking down ENTR1. Overexpression of ENTR1 could reverse this effect. RNA-seq analysis showed that tumor necrosis factor (TNF) signaling pathway might be a putative regulatory target of ENTR1. Tumor formation assay validated that ENTR1 was a significant factor in tumor growth.

Conclusion: Our results indicated that ENTR1 played an important role in cell proliferation, invasion and chemotherapeutic sensitivity of GBM, suggesting that ENTR1 might be a novel prognostic marker and significant therapeutic target for GBM.