Inhibition of migration and invasion by berberine via inactivation of PI3K/Akt and p38 in human retinoblastoma cell line.

BACKGROUND: As a clinically important natural isoquinoline alkaloid, berberine has been reported to possess various pharmacological effects.

OBJECTIVES: This study was aimed to investigate the effect of berberine on cell migration and invasion in human retinoblastoma (Rb) cells.

MATERIAL AND METHODS: The cytotoxicity of berberine was estimated by 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay. After being stimulated with berberine under various concentrations, the cell migration and invasion were evaluated by transwell assay. Then, the expression levels of epithelial-mesenchymal transition (EMT) markers were determined by quantitative reverse transcription PCR (qRT-PCR) and western blot analysis. Furthermore, the phosphorylation levels of protein kinase B (Akt) and p38 were detected by western blot analysis. Finally, the effect of phosphatidylinositol-3-kinase (PI3K) and p38 inhibitors on cell migration and invasion was estimated by transwell assay. Untreated cells acted as control for all the experiments.

RESULTS: The concentrations of berberine for further studies were controlled in a range of 0 to 100 μM. The cell migration and invasion were both suppressed by berberine in a dose-dependent manner compared to the control (p < 0.05 or p < 0.001). Berberine remarkably down-regulated expression of E-cadherin and up-regulated expression of vimentin and α-SMA compared to the control (p < 0.01 or p < 0.001). Furthermore, the phosphorylation levels of Akt and p38 were both down-regulated by berberine in comparison to the control. Furthermore, the addition of berberine accompanied by LY294002 or SB203580 significantly suppressed cell migration and invasion compared to the addition of berberine alone (p < 0.05).

CONCLUSIONS: Berberine suppressed cell migration and invasion via inactivation of PI3K/Akt and p38.