Overexpression of GBP1 predicts poor prognosis and promotes tumor growth in human glioblastoma multiforme.

OBJECTIVE: Guanylate binding protein-1 (GBP1) is highly associated with cell proliferation, and can modulate growth and invasiveness of gliomas. The relationship between GBP1 expression and the prognosis of glioma patients is further evaluated for the purpose of investigating whether GBP1 can serve as an predictor for evaluating prognosis of glioma patients.

METHODS: GBP1 expression in 528 glioblastoma multiforme (GBM) patients of The Cancer Genome Atlas (TCGA) database were investigated, then 103 surgical specimens from glioma patients in our center were further evaluated. The effect of GBP1 on proliferation, invasion and migration of glioma cells in vitro was analyzed, and the effects of GBP1 on sensitivity of radiotherapy and chemotherapy on glioma cells in vitro were also analyzed. GBP1 associated signaling pathways were identified with Gene Set Enrichment Analysis (GSEA). Besides, the effect of GBP1 expression on proliferation of glioma cells in vivo was analyzed.

RESULTS: In both TCGA database and our clinical data, GBM tissues exhibited increased mRNA expression of GBP1 gene, its expression level was co-related to PETN deletion and EGFR amplification, and was associated with prognosis of GBM patients. GBP1 overexpression can enhance migration and invasion ability of tumor cells in vitro, and in vivo studies showed that GBP1 can promote tumor proliferation, decrease survival in tumor-bearing mice. GSEA analysis predicted that GBP1 may play its biological roles via toll-like receptor pathway.

CONCLUSION: This study provides new insights and evidences that high level expression of GBP1 is significantly correlated with progression and prognosis in GBMs. Furthermore, transfection of GBP1 revealed its regulation on migration and invasiveness of glioma cells, decreasing sensitivity of chemotherapeutic agent, shortening survival of tumor-bearing animals. These data demonstrate that GBP1 may serve as a novel prognostic biomarker and a potential therapeutic target for gliomas.