Wogonin suppresses stem cell-like traits of CD133 positive osteosarcoma cell via inhibiting matrix metallopeptidase-9 expression

BACKGROUND Several efforts have been deployed to cure osteosarcoma, a high-grade malignant bone tumour in children and adolescents. However, some challenges such as drug resistance, relapse, and tumour metastasis remain owing to the existence of cancer stem cells (CSC). There is an urgent need to develop cost-effective and safe therapies. METHODS Wogonin, an extract from the root of Scutellaria baicalensis, has long been considered as a promising natural and safe compound for anti-tumourigenesis, particularly to inhibit tumour invasion and metastasis. Hoechst 33,342 staining, wound healing assay, sphere formation assay, western blotting, and gelatin zymography assays were performed in CD133 positive osteosarcoma cell. RESULTS In this study, we examined the effect of Wogonin on the mobility of human osteosarcoma CSC. Wogonin induces apoptosis of human osteosarcoma CSC, inhibits its mobility in vitro via downregulation of MMP-9 expression, and represses its renewal ability. CONCLUSIONS We demonstrated that Wogonin decreases the renewal capacity of CSC. By inhibiting the formation of and reducing the size of spheres, Wogonin at a concentration of 40-80 μM effectively minimizes potential risk from CSC. Taken together, we have demonstrated a new approach for developing a potential therapy for osteosarcoma.