Schisandrin B induces growth inhibition and apoptosis of human Ewing sarcoma cells in vitro

Objective To investigate the effect of Schisandrin B (Sch B) on growth inhibition and apoptosis of human Ewing sarcoma cells in vitro, and to explore its possible mechanism. Methods Ewing sarcoma cell line A673 was treated with Sch B in vitro. The inhibitory effect of Sch B on the proliferation of Ewing sarcoma cells was studied by methyl thiazol tetrazolium (MTT) assay (0, 10, 20, 50, 100 μmol/L). Colony forming experiment was used to explore the inhibitory effect of Sch B on the colony formation of Ewing sarcoma cells (0, 5, 10, 15 μmol/L). The expression of B cell lymphoma/leukemia-2 (bcl-2), bcl-2 associated X protein (bax), p53 and Cyclin D1 protein was detected by Western blotting (10, 20, 50 μmol/L). Results The results showed that Sch B effectively inhibited cell growth and induced apoptosis of human Ewing sarcoma cell line A673 (18.22%, 22.50%, 34.43%, 53.56%) in a time- and dose-dependent fashion. Sch B also significantly inhibited the colony forming ability of Ewing sarcoma cells (110.5±12.4, 82.2±14.1, 54.3±9.2, 38.4±16.5). Sch B could significantly down-regulate the expression of bcl-2 and Cyclin D1n, and significantly up-regulate the expression of bax and p53. Conclusion Our findings demonstrate that Sch B can significantly inhibit the proliferation of Ewing sarcoma cell line A673, which may be related with the down-regulation of bcl-2 and Cyclin D1, and up-regulation of bax and p53. Key words: Schisandrin B; Ewing sarcoma; Apoptosis; B cell lymphoma/leukemia-2