ABSTRACT
In this study, we investigated the inhibitory effects of bufalin on proliferation, migration and invasion of PC3 cells in vitro, and preliminarily explored the molecular mechanism of epithelial-mesenchymal transformation (EMT) inhibited by bufalin. The viability of PC3 cells was evaluated by MTT assay, and the migration and invasion abilities of PC3 cells were detected by wound healing and Transwell assay. Western blot was used to detect the expression of EMT and integrin family proteins. The results showed that the half maximal inhibitory concentration (IC50) value of bufalin against PC3 cells was 0.26 ± 0.03 μmol·L-1. After bufalin treatment, the migration rate of PC3 cells slowed down (P < 0.05), the number of PC3 cells passing through the microporous membrane decreased (P < 0.05), which indicated that bufalin could inhibit the proliferation, migration and invasion of PC3 cells in a concentration-dependent manner. We found that bufalin could affect the expression of EMT-related proteins,including up-regulation of E-cadherin and down-regulation of N-cadherin, β-catenin, matrix metalloproteinase 9 (MMP9), matrix metalloproteinase 2 (MMP2), c-myc and Snail. Bufalin also inhibited the expression of integrin family proteins, including integrin α2 (ITGA2), integrin β1 (ITGB1), integrin β3 (ITGB3), integrin β5 (ITGB5), Yes-associated protein/transcriptional coactivator with a PDZ-binding motif (YAP/TAZ) and integrin-linked kinase (ILK). In addition, bufalin could also inhibit the protein expression level of phospho-focal adhesion kinase (p-FAK)/FAK, phospho-steroid receptor coactivator (p-Src)/Src and phospho-protein kinase B (p-Akt)/Akt. These results suggested that bufalin might inhibit the proliferation, metastasis and invasion of prostate cancer PC3 cells through the FAK/Src/phosphoinositide 3-kinase (PI3K)/Akt pathway. Therefore, bufalin provides reference value for the development of therapeutic drugs for prostate cancer.