Effect of FoxM1 inhibitor thiostrepton on proliferation and apoptosis of Daoy cells in medulloblastoma

Abstract

Objective To investigate the effect of FoxM1 inhibitor thiostrepton on proliferation and apoptosis of Daoy cell line in medulloblastoma.Methods Daoy cells from medulloblastoma were routinely cultured in vitro,and they were treated with thiostrepton at various concentrations (0,1,1.5,2,3 and 5 μmol/L); the mRNA and protein levels of FoxM1 were detected by real-time PCR and Western blotting 48 h after treatment; the proliferation of Daoy cells was investigated using CCK-8 assay 24,48 and 72 h after treatment; flow cytometry was used to observe the changes of cycle and apoptosis of Daoy cells after thiostrepton treatment; the effects of thiostrepton on apoptosis-relating proteins of Bcl-2 and Bax were studied using Western blotting.Results Thiostrepton could obviously inhibit Daoy cell proliferation in time-and dose-dependent manners,with significant difference between each two concentrations (P＜0.05),and IC50 at 24,48 and 72 h after treatment was (2.1±0.15),(1.69±0.11) and (1.39±0.1) μmol/L.As thiostrepton concentration increased,FoxM1 mRNA and protein expressions gradually decreased in Daoy cells; increasing thiostrepton concentration induced Daoy cell cycle being gradually blocked at G2/M phase,decreased Bcl-2 expression,up-regulated Bax expression and significantly increased apoptosis rate,with significant differences between each two concentrations (P＜0.05).Conclusion FoxM1 inhibitor Thiostrepton can obviously inhibit Daoy cell proliferation,which might be related to cells being arrested at G2/M stage and apoptosis being induced by Bcl-2/Bax expression proportion changes. Key words: Thiostrepton; FoxM1; Medulloblastoma; Cell proliferation