Effects of Inhibiting Notch Signaling Pathway Combined with Silencing Id1 on the Malignant Biological Behavior and Osteogenic Differentiation in Osteosarcoma

CHEN Jie, ZHANG Yao, XIE Shengnan, ZHOU Hong, LUO Qing^*

(Department of Pediatric Research Institute of Children’s Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders (Chongqing), Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Chongqing 400014, China)

Abstract:

The aim of the research is to study effect of inhibiting Notch signaling pathway combined with silencing Id1 on biological behavior and osteogenic differentiation of human osteosarcoma cell MG63. MG63 cells were treated with the Notch signaling pathway inhibitor DAPT and silencing Id1 alone or jointly. The expression of Notch1, Jagged1, Id1 in each group was detected by Western blot. CCK8 was used to detect the proliferation ability of MG63 cells in different groups. Flow cytometry was used to detect the apoptosis level of MG63 cells in different groups. Scratch test and Transwell were used to detect the migration and invasion abilities of MG63 cells in different groups. Alkaline phosphatase and Alizarin red staining were used to detect the early and late-stage osteogenic differentiation abilities of MG63 cells in different groups, respectively. The results indicate that DAPT can inhibit the Notch signaling pathway with the down-regulated expression of Notch1 and Jagged1 (P<0.05). The Id1 expression decreased after inhibiting the Notch signaling pathway of MG63 cells, and the Id1 expression level was lowest after inhibiting the Notch signaling pathway combined with silencing Id1 of MG63 cells (P<0.05). The proliferation, migration, invasion ability and the early-stage osteogenic differentiation ability decreased, but the apoptosis level increased after inhibiting the Notch signaling pathway of MG63 cells (P<0.05). After inhibiting the Notch signaling pathway combined with silencing Id1 of MG63 cells, the proliferation, migration and invasion ability decreased further, but the osteogenic differentiation ability increased, meanwhile the apoptosis level was the highest (P<0.05). To sum up, inhibiting the Notch signaling pathway can weaken MG63 cells malignancy. While, inhibiting the Notch signaling pathway combined with silencing Id1 can further weaken the malignancy of MG63 cells. It can also promote MG63 osteogenic differentiation.