Objective To investigate the effect of EN2 on the apoptosis and PTEN protein expression in hepatocellular carcinoma cells.

Methods Hepatoma cells HuH-7 was infected with EN2 siRNA lentivirus. qRT-PCR and Western blot methods were used to detect the interference effect. The changes of cell vitality was measured by MTT method, PI single staining method was used to determine cell cycle distribution, the apoptosis was measured by Annexin V-FITC/PI double staining, Western blot was used to measure the levels of Cleaved Caspase-3, Cleaved Caspase-9, PTEN and Cyclin B1 protein, the changes of mitochondrial membrane potential was measured by JC-1 method, and Western blot was used to measure the level of Cytochrome C protein in the cytoplasm.

Results EN2 siRNA lentivirus infection could significantly reduce the expression of EN2 in hepatocellular carcinoma cells. After EN silence, the activity of hepatoma cells was decreased, the rate of apoptosis was increased, the proportion of G2/M phase in cells was increased, the levels of Cleaved Caspase-3, Cleaved Caspase-9 and PTEN protein were increased significantly, the level of Cyclin B1 protein was decreased significantly, the mitochondrial membrane potential was decreased, and the level of Cytochrome C protein in the cytoplasm was increased.

Conclusion Knockdown of EN2 could block the cell cycle of liver cancer and induce the apoptosis of hepatoma cells, and the mechanism may be related to PTEN and mitochondrial apoptotic pathway.