Objective To assess the ability of plumbagin to inhibit invasion by osteosarcoma and explore possible mechanisms. Methods Osteosarcoma MG-63 cultures were treated for 24 h with 0.1% DMSO only（control） or with plumbagin at 2.5，5 and 10 μmol/L. Then the invasive ability of the MG-63 cells was measured in a trans-well assay，changes in Ezrin mRNA levels were determined using real-time PCR，and changes in Ezrin and p-Ezrin protein levels were assessed using Western blot assay. Results Plumbagin treatment reduced the number of invading artificial basement cells in a dose-dependent manner，and rate of cell migration at the three plumbagin doses was respectively，69.9±4.5%，39.3±3.5% and 26.2±4.1% of control cells（P<0.05）. Real-time PCR showed that plumbagin significantly reduced level of mRNA in a dose-dependent manner（P<0.05）. Similarly，Western blotting showed that plumbagin significantly reduced levels of Ezrin and p-Ezrin in a dose-dependent manner. Conclusion Plumbagin may inhibit tissue invasion by osteosarcoma MG-63 cells，and it may do so in part by suppressing Ezin and p-Ezrin expression.
