PCGF1 is a prognostic biomarker and correlates with tumor immunity in gliomas.

Background: Polycomb group factor 1 (PCGF1) plays a vital role in the self-renewal of cancer stem cells (CSCs). However, the prognostic value and potential function of PCGF1 in glioma progression, especially in tumor immunity, remain unclear. Methods: This study investigated PCGF1 expression in pan-cancers and glioma using The Cancer Genome Atlas Project data, and conducted a logistic regression analysis to analyze the association between PCGF1 expression and the clinicopathological features of glioma patients. Kaplan-Meier and Cox regression analyses were used to assess the prognostic roles of PCGF1. The functional analysis using gene ontology and Kyoto Encyclopedia of Genes and Genomes databases and a gene set enrichment analysis (GSEA) were conducted to examine the PCGF1-related biological processes and signaling pathways. Finally, the roles of PCGF1 in immune infiltration were analyzed by a single sample GSEA (ssGSEA). Results: PCGF1 expression was upregulated in glioma tissues. The high expression of PCGF1 was significantly associated with an age >60 years (P<0.001), an increased World Health Organization grade (P<0.001), and wildtype isocitrate dehydrogenase (IDH) status (P<0.001), and predicted poor overall survival (OS) [hazards ratio (HR) =2.90, 95% confidence interval (CI): 2.25-3.74; P<0.001], the progression-free interval (PFI) (HR =1.99, 95% CI: 1.60-2.46; P<0.001), and disease specific survival (DSS) (HR =2.84, 95% CI: 2.18-3.71; P<0.001). The multivariate regression analysis confirmed that PCGF1 expression was an independent prognostic factor of OS (HR =1.581, 95% CI: 1.161-2.153; P=0.004). Based on the functional enrichment analysis, we identified the PCGF1-related differentially expressed genes (DEGs), and found that PCGF1 was involved in regulating many oncogenic signaling pathways, such as the phosphatidylinositol 3-kinase and protein kinase B pathway, the Janus kinase/signal transducers and activators of transcription (JKT-STAT) signaling pathway, notch signaling and integrin signaling pathway. In addition, we found that PCGF1 expression was positively associated with the abundance of Th2, but negatively associated with T follicular helper, T central memory, and T gamma delta cells. Additionally, PCGF1 participated in the regulation of numerous immune-related processes in glioma. Conclusions: PCGF1 is a promising prognostic biomarker, and as it governs cancer-related pathways and tumor immunity, it plays an important role in glioma development.