| Objective To investigate the effects of Notch1 signaling pathway mediated by γ-secretase inhibitor (DAPT) on proliferation, apoptosis, invasion and metastasis of osteosarcoma MG-63 cell line in hypoxia. Methods The osteosarcoma cell line MG-63 was divided into normal group (NC), hypoxic group (Hypoxia), and hypoxic group containing DAPT as experimental group (Hypoxia+DAPT). Flow cytometry was used to detect the cell cycle after treatment, CCK-8 method was used to detect the proliferation ability of cells, and Western Blot was used to detect the expression of Notch-1, HIF-1α and Hes-1 proteins in MG-63 cell line. To verify its transfer ability through Transwell experiment. At the same time, the effects of DAPT on cell proliferation and cell cycle in hypoxic environment were investigated. The down-regulation of Notch1 and the inhibition of hypoxia on MG-63 cells were analyzed. Results Compared with the normal group, the proliferative capacity and invasive ability of the hypoxic group were significantly higher than those of the normal group, and the difference was statistically significant (P<0.05). Compared with the hypoxic group, the γ-secretase inhibitor (DAPT) significantly reduced the proliferation and invasion ability of the experimental group (P<0.05). Western Blot results showed that both the hypoxic group and the experimental group up-regulated the expression of Notch1, HIF-1α, and Hes-1 related proteins compared with the normal group, but the experimental group significantly down-regulated Notch1 and HIF-1α, Hes-1 protein expression level compared with the hypoxic group. (P<0.05). Flow cytometry results showed that compared with the normal group, both the hypoxic group and the experimental group could promote the cell from G1 to G2 phase, but compared with the hypoxic group, the experimental group significantly inhibited the cell from G1 to G2 phase, making the cell cycle stagnant and the difference was statistically significant (P < 0.05). The results of proliferation experiments showed that compared with the normal group, both the hypoxic group and the experimental group could promote cell proliferation, but compared with the hypoxic group, the experimental group significantly inhibited cell proliferation, and the difference was statistically significant (P<0.05). Conclusion γ-Secretase inhibitor (DAPT) can significantly inhibit the proliferation and invasion of osteosarcoma cell line MG-63 by down-regulating Notch1 pathway. Down-regulating Notch1 expression may be one of the potential mechanisms for the treatment of osteosarcoma. |
