Brucine suppresses breast cancer metastasis via inhibiting epithelial mesenchymal transition and matrix metalloproteinases expressions

To examine the effect of brucine on the migration, invasion, adhesion and expressions of epithelial-to-mesenchymal transition (EMT) markers and matrix metalloproteinases (MMPs) in the highly metastatic breast cancer cell lines MDA-MB-231 and Hs578-T. MDA-MB-231 and Hs578-T cells were divided to 4 groups: the control group (0.1% DMSO), and 25, 50 and 100 mu mol/L brucine groups. The cell viability was determined using a CellTiter-GloA (R) luminescent cell viability. The scratch wound healing assay and tanswell migration assay were used to determine the migration ability of these cells treated by different concentrations of brucine. The proliferation rate, invasive potential and adhesive ability were respectively performed by colony formation assay, transwell invasion assay and adhension assay. The protein and mRNA expressions of EMT biomarkers, MMP-2 and MMP-9 were investigated by real-time reverse transcription polymerase chain reaction and Western blot. Compared with the control group, brucine had little effect on cell viability or proliferation (P > 0.05), but led to a dose-dependent decrease on migration, invasion, adhension of MDA-MB-231 and Hs578-T cells (P < 0.01). Furthermore, brucine increased the protein and mRNA levels of EMT markers such as E-cadherin and beta-catenin in MDA-MB-231 and Hs578-T cells, and decreased the protein and mRNA levels of mesenychmal markers such as vimentin and fibronectin, as well as the expressions of MMP-2 and MMP-9 (all P < 0.01). Brucine inhibited triple negative breast cancer cells metastasis potentially through EMT reversion and MMP-2 and MMP-9 inhibition.