RESUMO
Objective To explore whether PI3K inhibitor combined with oncolytic virus can play an effective oncolytic effect on osteosarcoma. Methods The cytotoxicity to tumor cells was detected by MTT method, and the mechanism of enhancing the anti-tumor activity was explored by observation of the swelling of endoplasmic reticulum using electron microscope and the expression of apoptosis-related proteins using Western blotting. The tumor clearance ability of the combination of the PI3k inhibitor ZSTK474 and vesicular stomatitis virus A51 (VSVA51) was verified by anti-tumor experiment in vivo. The apoptosis of tumor cells was verified by immunohistochemistry. Results PI3K inhibitor could be used as sensitizers of oncolytic VSVA51, and confirmed that the)' promoted the strong apoptosis of osteosarcoma cells by aggravating the stress of endoplasmic reticulum in tumor cells (P < 0 . 01). In vivo experiments also showed that PI3K inhibitors combined with VSVA51 could significantly promote the oncolytic effect of osteosarcoma (P<0.001), and this combination therapy enhanced the infiltration of immune cells in the tumor (P<0.001). Conclusion PI3K inhibitors combined with oncolytic virus is a potential therapy for osteosarcoma.
RESUMO
BACKGROUND: It is an urgent problem to effectively make bone marrow mesenchymal stem cells exert proper effects under hypoxic preconditioning. OBJECTIVE: To investigate the effects of diazoxide, a Mito-KATPchannel activator, on the proliferation and apoptosis of mouse BMSCs in hypoxic environment. METHODS: Mouse BMSCs were divided into four groups: blank control group, 0.16, 0.8, 4 μmol/L diazoxide groups. Cells intervened by diazoxide were cultured in a 10% O2incubator. MTT assay was performed to detect cell proliferation at 1, 2, 4, 6, 8 days after intervention, and Hoechst 33258 staining was performed to observe cell apoptosis at 14 days after intervention. RESULTS AND CONCLUSION: High homogeneity and purity but low proliferation of BMSCs was found. There was no significant difference in the activity of BMSCs among 0.16, 0.8, 4 μmol/L diazoxide groups (P > 0.05). In the blank control group, concentrated nuclei were dark blue in color and aggregated, and several round apoptotic bodies were found. In the diazoxide groups, apoptotic bodies were occasionally found, and no significant difference was found among different diazoxide groups. These findings indicate that a certain concentration of diazoxide can reduce cell apoptosis but has no effects on the proliferation of mouse BMSCs under hypoxic environment (10% O2).