Effects of thymoquinone on growth and apoptosis of osteosarcoma SaOS-2 cell line in vitro

Abstract

Objective To investigate the inhibitory effect of thymoquinone on the growth of human osteosarcoma cell line SaOS-2 in vitro.Methods After human osteosarcoma SaOS-2 cells were treated with different concentrations of thymoquinone, the proliferation was measured by Cell Counting Kit-8 (CCK-8) assay. The flowcytometry (FCM) was used to determine apoptosis of SaOS-2 cells. The morphological changes of SaOS-2 cells were observed under the fluorescence microscopy after DAPI staining. Western blotting was used to detect the protein expression of Caspase-3, X-linked inhibitor of apoptosis protein (XIAP) and Smac.Results Thymoquinone obviously suppressed proliferation of SaOS-2 cells in a dose-dependent manner, and the apoptosis rate was (8.1±0.7)%, (13.2±1.1)% and (20.2±1.7)% respectively when the concentrations of thymoquinone exposed were 20, 40 and 80 μmol/L. After treatment with thymoquinone, the expression of Caspase-3 and Smac was up-regulated in SaOS-2 cells, and thymoquinone treatment significantly decreased the XIAP levels in SaOS-2 cells.Conclusion Thymoquinone has the anti-tumor effect on the human osteosarcoma SaOS-2 cells in vitroprobably by up-regulating the expression of Caspase-3 and Smac and down-regulating the expression of XIAP. Key words: Thymoquinone; Osteosarcoma; Apoptosis