Ursolic acid can effectively inhibit the proliferation of osteosarcoma cell line U2-OS. - GreenMedInfo Summary

Objective: To investigate the effect of ursolic acid on the proliferation and apoptosis of human osteosarcoma cell line U2-OS and analyze its mechanism.

Methods: Human osteosarcoma cell line U2-OS was divided into 4 groups, which was cultured with ursolic acid of 0, 10, 20, and 40μmol/L, respectively. At 0, 24, 48, and 72 hours after being cultured, the cell proliferation ability was detected by cell counting kit 8 (CCK-8). At 48 hours, the effects of ursolic acid on cell cycle and apoptosis of U2-OS cells were measured by flow cytometry. Besides, the expressions of cyclinD1 and Caspase-3 were detected by real-time fluorescent quantitative PCR and Western blot.

Results: CCK-8 tests showed that the absorbance () value of each group was not significant at 0 and 24 hours (>0.05); but the differences between groups were significant at 48 and 72 hours (<0.05). Flow cytometry results showed that, with the ursolic acid concentration increasing, the Gphase of U2-OS cells increased, the S phase and G/M phase decreased, and cell apoptosis rate increased gradually. There were significant differences between groups (<0.05). Compared with the 0μmol/L group, the relative expressions of cyclin D1 mRNA and protein in 10, 20, and 40 μmol/L groups significantly decreased (<0.05); whereas, there was no significant difference in relative expression of Caspase-3 mRNA between groups (>0.05). However, with the ursolic acid concentration increasing, the relative expressions of pro-Caspase-3 protein decreased and the relative expressions of activated Caspase-3 increased; there were significant differences between groups (<0.05).

Conclusion: Ursolic acid can effectively inhibit the proliferation of osteosarcoma cell line U2-OS, induce the down-regulation of cyclin D1 expression leading to G/Gphase arrest, increase the activation of Caspase-3 and promote cell apoptosis.