To investigate the relationship between CDC42EP2 gene and prognosis, immune cell infiltration in patients with hepatocellular carcinoma (HCC) and its effects on cell migration and invasion.

The expression profile data of CDC42EP2 gene in HCC and normal liver tissues were downloaded from The Cancer Genome Atlas (TCGA) database. The correlation between CDC42EP2 gene expression in HCC tissues and clinicopathological characteristics was analyzed. Survival analysis was performed by Kaplan-Meier Plotter. The co-expression network of CDC42EP2 was determined by using HCCDB database. The correlation between CDC42EP2 expression and immune cell infiltration was evaluated by using TIMER2.0 database. The expression of CDC42EP2 gene in HepG2 cells was suppressed by siRNA technology. The effects of CDC42EP2 on cell migration and invasion were assessed byqRT-PCR and Transwell chamber assay.

TCGA database analysis showed that the expression level of CDC42EP2 in HCC tissues was significantly higher than that in normal liver tissues (P<0.05). Expression of CDC42EP2 in HCC tissues was correlated with histopathological grade, TNM stage and TP53 mutation (P<0.05). The median survival of patients with high expression of CDC42EP2 in HCC tissues was 41.0 months, significantly shorter than 84.4 months of those with low CDC42EP2 expression (HR=1.86, P<0.05). The expression level of CDC42EP2 was positively associated with the infiltration of helperT cells (Th), central memory T cells (Tcm) and Th2 cells, but negatively associated with the infiltration of dendritic cells (DC) and Th17 cells (r=0.179, 0.172, 0.144, -0.125, -0.182; P<0.05). After CDC42EP2 gene was knockdowned by siRNA technology, the migration and invasion capabilities of HepG2 cells were significantly weakened.

CDC42EP2 gene is highly expressed in HCC, which is correlated with poor prognosis of HCC patients. Knockdown of CDC42EP2 gene can inhibit the migration and invasion of HCC cells.