Carcinogenesis effects of E2F transcription factor 8 (E2F8) in hepatocellular carcinoma outcomes: an integrated bioinformatic report

This report aimed to investigate the carcinogenesis effects of E2F transcription factor 8 (E2F8) in hepatocellular carcinoma (HCC). E2F8 expression level was compared in Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA) and Oncomine. Survival analysis of E2F8 for HCC were conducted in Kaplan-Meier plotter. Correlations of E2F8 and clinico-pathological features were performed in TCGA. Enrichment of interacted and similar genes with E2F8 was evaluated in Gene Set Enrichment Analysis (GSEA) and Metascape. We found that E2F8 was significantly up-regulated in tumor tissues compared with nontumor tissues (all P < 0.01). Moreover, E2F8 was significantly overexpressed in peripheral blood mononuclear cell (PBMC) in HCC patients than that in healthy individuals (P < 0.001). Meta-analysis in Oncomine database confirmed that E2F8 was significantly higher in HCC tumors (P = 4.28E-08). Additionally, E2F8 elevation significantly correlated with overall survival (OS), recurrence-free survival (RFS), disease-specific survival (DSS) and progression-free survival (PFS) in HCC patients (all P < 0.01). E2F8 level was significantly higher in HCC patients with advanced neoplasm histologic grade, American Joint Committee on Cancer (AJCC) stage and a-fetoprotein (AFP) elevation (all P < 0.05). Cox regression model demonstrated that high E2F8 was an independent risk factor for OS and DFS in HCC patients (HR = 2.16, P = 0.003 and HR = 1.64, P = 0.002, respectively). Enrichment analysis revealed that genes interacted/similar with E2F8 were mainly enriched in cell cycle pathways/biological process. Conclusively, up-regulated in tumors, E2F8 might accelerate tumor progression and result in unfavorable outcomes in HCC patients.