BACKGROUND: Berberine (BBR) is an isoquinoline alkaloid extracted from Huang Lian and other herbal medicines. It has been reported to play a crucial role in multiple metabolic diseases and cancers. Programmed cell death-1 (PD-L1) is known as the immune checkpoint
immunotherapy targeting PD1/PD-L1 axis can effectively block its pro-tumor activity. However, the effect of the combined use of BBR and anti-PD-L1 on hepatocellular carcinoma (HCC) has not been reported. METHODS: Hep-3B and HCCLM3 cells were chosen as the experimental objects. To determine the potential anti-cancer activity of the combination of BBR and anti-PD-L1, we first treated v cells with BBR. The cell viability of Hep-3B and HCCLM3 with BBR treatment was measured by Cell Count Kit 8 assay. Cytometry by time-of-flight was performed to analyze tumor tissues after treatment with BBR and/or anti-PD-L1. Proliferation-, migration-, and invasion-related markers were measured by western blotting and immunohistochemistry. RESULTS: The results showed that BBR significantly inhibited the proliferation of Hep-3B and HCCLM3.The combination treatment of BBR and anti-PD-L1 had a prominent inhibitory effect on HCC tumorigenesis. Cytometry by time-of-flight analysis indicated that BBR affects the immune subsets in the tumors. Besides, BBR and anti-PD-L1 inhibited the migration and invasion of HCC by inactivating the phosphorylation of Erk. CONCLUSION: Our study proposed that the combination treatment of BBR and anti-PD-L1 markedly inhibited the tumorigenesis of HCC by Erk signaling pathway. We hope our research can provide a new strategy for the potential of BBR as a therapeutic agent in the treatment of HCC.