Notch Signaling Pathway Regulates Epithelial-mesenchymal Transition of Osteosarcoma by Activating Slug

Abstract

Objective To investigate the effect and mechanism of Notch signaling pathway on epithelial-mesenchymal transition (EMT) of osteosarcoma. Methods We used lentivirus transfection technology to transfect osteosarcoma cells, and used si-slug to knock down the Slug gene. Then we used immunofluorescence staining, Western blot, qRT-PCR, phase contrast microscopy, wound healing and TranswellTM test to detect the morphological, the invasion and metastasis and the influences of EMT of the corresponding osteosarcoma cells. In animal experiments, the volume and weight of nude mice were compared after tumorigenesis, and the expression of Slug and N-cadherin in tumor tissues were detected by qRT-PCR. Results We successfully obtained osteosarcoma cells with activated or inhibited Notch signaling pathway. In Notch activated group, the expression of N-cadherin was increased significantly, the ratio of long/short axis, the expression of Slug and Twist1, as well as the invasion and metastasis abilities of osteosarcoma cells were increased. Animal experiments showed that activated Notch signaling pathway could promote tumorigenesis in vivo, and the positive rates of Slug and N-cadherin in osteosarcoma tissues in xenograft were upregulated. The morphology, invasion and metastasis of osteosarcoma cells in the Notch activated group were reversed after Slug was successfully knocked out. Conclusion Notch signaling pathway promotes the EMT of osteosarcoma, which may be related to Slug activation.

Keywords

• osteosarcoma
• emt
• notch signaling pathway
• slug