High expression of RFX4 is associated with tumor progression and poor prognosis in patients with glioblastoma.

Glioma stem cells (GSCs) have been shown to contribute to tumor development and recurrence, therapeutic resistance, and cellular heterogeneity of glioblastoma multiforme (GBM). Recently, it has been reported that GSCs lose their self-renewal ability and tumorigenic potential upon differentiation. In this study, we identified Regulatory Factor X4 () gene to regulate GSCs' survival and self-renewal activity in the GBM patients samples. We utilized public datasets from the Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), Ivy Glioblastoma Atlas Project, and The Human Protein Atlas to screen candidate genes which are associated with the development of GBM and poor patients survival. Small hairpin RNA (shRNA) lentivirus was applied to knockdown gene in GSCs. We found that mRNA expression among the RFX family was particularly reduced during GSC differentiation. RT-qPCR analysis revealed significant downregulation of and stem cell markers ( and ) mRNA expressions in primary human GBM-derived GSCs cultured under serum condition. Consistently, GSCs showed significantly elevated mRNA expression levels compared to normal astrocytes, NHA, whereas glioma cells did not. Furthermore, analysis of the TCGA data set revealed that is highly expressed in GBM, and contributes to the lowering of patient survival. Depletion of using shRNA lentivirus in patient GBM-derived GSCs decreased neurosphere formation and cell viability. These results suggest that RFX4 is a potential risk factor for maintaining the stemness of GSCs and making glioma more malignant, and thus, could be a promising target of GBM treatment.