Background: Berberine (BBR), a natural isoquinoline alkaloid, possesses diverse pharmacological properties and anti-cancer effects that have been demonstrated in many in vitro and in vivo studies. In this study, the inhibitory effects and molecular mechanism of low dose BBR on EMT-induced cell migration, and invasion capability of cholangiocarcinoma (CCA) cell lines were demonstrated.
Methods: The commercially available BBR chloride powder with purity ≥ 95% was used in this study. Effects of BBR on cell growth of two human CCA cell lines, KKU-213A and KKU-213B were measured using MTT assay. The progressive phenotypes-cell adhesion, migration, and invasion were evaluated using cell adhesion, wound healing, and Boyden chamber assays. Molecular docking analysis was performed to assess the possible binding mode of BBR against EGFR, Erk, STAT3 and Akt. The effects of BBR on the activations of EGF/EGFR and its downstream effectors were demonstrated using Western blotting.
Results: BBR inhibited growth of CCA cells in a dose dependent manner. At sub-cytotoxic dose, BBR significantly inhibited cell adhesion, migration, invasion and decreased expression of vimentin, slug, and VEGFA of both CCA cell lines. Molecular docking suggested the simultaneous inhibitory activity of BBR on EGFR, Erk, STAT3 and Akt. The Western blot analyses revealed that upon the EGF/EGFR activation, BBR considerably attenuated the activations of EGFR, Erk, STAT3 and Akt.
Conclusion: Low dose of BBR suppresses EMT and thus aggressiveness of CCA cells, in part by its multi-kinase inhibitor property on EGFR and its downstream pathways. BBR might be beneficial for therapy of human CCA.
Keywords: Benzylisoquinoline alkaloid; Bile duct cancer; EGFR; VEGFA; epithelial-mesenchymal transition.