Expression Levels of Three Key Genes CCNB1, CDC20, and CENPF in HCC Are Associated With Antitumor Immunity

Hepatocellular carcinoma (HCC) is the most common primary liver cancer with a low 5-year survival rate. The heterogeneity of HCC makes monotherapy unlikely. The development of diagnostic programs and new treatments targeting common genetic events in the carcinogenic process are providing further insights into the management of HCC. The aim of this study was firstly to validate key genes that are involved in promoting HCC development and as biomarkers for early diagnosis and, secondly, to define their links with antitumor immunity including inhibitory checkpoints.

Multiple databases including Gene Expression Omnibus (GEO), Gene Expression Profiling Interactive Analysis (GEPIA), Kaplan-Meier Plotter, UALCAN, and Oncomine were used for target gene screening and establishment of a co-expression network. Clinical data and RNAseq of 367 HCC patients were downloaded from the Cancer Genome Atlas (TCGA) database. The diagnostic and prognostic value of screened genes were tested by receiver operating characteristic (ROC) curve and correlation analysis. The links with the key genes in HCC and antitumor immunity were defined using both blood and liver tissue collected prospectively from HCC patients in our center.

Upregulation of CCNB1, CDC20, and CENPF was commonly observed in HCC and are involved in the p53 signal pathway. The hepatic mRNA expression levels of these three genes were strongly associated with patients' prognosis and expressed high value of area under the ROC curve (AUC). Further analysis revealed that these three genes were positively correlated with the gene expression levels of IFN-γ, TNF-α, and IL-17 in peripheral blood. In addition, the expression of CENPF showed positive correlation with the percentage of CD8^pos T cells and negative correlation with the percentage of CD4^pos T cells in the peripheral blood. In the HCC microenvironment, the transcript levels of these three genes and inhibitory checkpoint molecules including PD-1, CTLA-4, and TIM-3 were positively correlated.

The upregulation of CCNB1, CDC20, and CENPF genes was a common event in hepatocarcinogenesis. Expression levels of CCNB1, CDC20, and CENPF showed potential for early diagnosis and prediction of prognosis in HCC patients. There is a close association between three genes and Th1/Th17 cytokines as well as the count of CD4^pos and CD8^pos T cells. The positive correlation between the three genes and inhibitory checkpoint genes, PD-1, CTLA-4, and TIM-3, indicates that these genes are linked with weakened antitumor immunity in HCC. Our findings may provide further insights into developing novel therapies for HCC.