Screening and in Vitro Activity of Novel Inhibitors That Targeting the SOAT1 Protein

OBJECTIVE  To screen inhibitors that targeting sterol O-acyltransferase 1(SOAT1) protein, and to investigate the effects of the potential inhibitors in vivo.

METHODS  Hepatoma cells with high SOAT1 expression were screened through CCLE database and used as experimental cell models. Molecular docking between 61 742 compounds from Interbioscreen database and SOAT1 protein was performed using the Autodock Vina software, and the binding energies were calculated. Eight compounds with relative high binding energy were selected, and their effects on the viability of hepatoma cells were detected using CCK8 assays. The two most active compounds in cell models were selected for further study, and their IC₅₀ were determined. Wound healing and crystal violet staining assays were employed to detect the effects of the two compounds on the migration and proliferation of hepatoma cells. Western blotting was used to study the effects of the compounds on SOAT1 protein in hepatoma cells. siRNA were transfected into hepatoma cells to construct a SOAT1-silenced cell model, and effects of the compounds on cell viability were tested.

RESULTS  Hep3B and PLC/PRF/5 human hepatoma cell lines with high expression of SOAT1 protein selected from the CCLE database as model cells were screened and used as cell models. Among the 8 compounds with relative high binding affinity screened by molecular docking, Compounds 1 and 7 had the most significant inhibitory effects on the viability of the two types of liver cancer cells mentioned above. Moreover, the two compounds inhibited cell migration and cell colony formation, as well as decreased SOAT1 protein expression in hepatoma cells. In SOAT1-silenced hepatoma cells, the inhibitory effects of the two compounds on cell viability were significantly attenuated.

CONCLUSION  Compound 1 and compound 7 exert anti-hepatoma effects at the cellular level by inhibiting the expression of SOAT1 protein, suggesting that these two compounds have the potential to be developed into SOAT1 inhibitors for the treatment of liver cancer.