摘要目的：探讨盐霉素对Hedgehog信号通路的调控作用及盐霉素抑制乳腺癌细胞MDA-MB-231增殖的作用机制。方法培养人乳腺癌细胞MDA-MB-231，在不同浓度盐霉素及不同作用时间下，采用CCK-8比色法检测盐霉素对MDA-MB-231细胞生长的影响，采用流式细胞术观察经盐霉素作用后细胞周期的改变，采用即时定量PCR和Western blot检测盐霉素处理后Hedgehog通路中靶基因Shh、Smo、Gli1的mRNA和蛋白表达的变化。结果盐霉素可以抑制MDA-MB-231的增殖，0、0.4、0.8和1.6μmol／L 作用48 h后抑制率分别为11.18％、25.88％、50.03％和92.65％。盐霉素能够阻滞MDA-MB-231细胞由 G1期进入 S 期，0、0.8和1.6μmol／L 的 S 期比率分别是25.03％、11.85％和35.21％。盐霉素抑制Shh、Smo以及Gli1的mRNA和蛋白的表达具有剂量依赖性。结论盐霉素可以阻滞MDA-MB-231细胞由G1期进入S期，其机制可能是通过下调Hedgehog通路中相关靶基因的表达进而抑制细胞增殖。

abstractsObjective To investigate the inhibitory effect of salinomycin on human breast cancer cells in vitro, and to explore the related molecular mechanism.Methods Human breast cancer MDA-MB-231 cells were treated with salinomycin at different concentrations and at various time points.The effect of salinomycin on MDA-MB-231 cells proliferation was studied by CCK-8 method.The cell cycle status was examined by flow cytometry.RT-PCR and Western blot were used to detect the expression of Shh, Smo and Gli1 in the Hedgehog pathway at mRNA and protein levels.Results Proliferation of MDA-MB-231 cells treated with salinomycin was markedly inhibited in a concentration and time dependent manner.Salinomycin at concentrations of 0,0.4,0.8 and 1.6 μmol/L inhibited the growth at the rates of 11.18%,25.88%, 50.03%, 92.65%, respectively.Salinomycin prevented MDA-MB-231 cells from G1 into S phase.Salinomycin at concentrations of 0,0.8 and 1.6μmol/L resulted in S-phase percentage of 25.03%,11.85%and 35.21%, respectively ( P <0.05 ).RT-PCR and Western blot showed that the expression of key elements Shh, Smo and Gli1 in the Hedgehog pathway was inhibited by salinomycin in a concentration dependent manner( P<0.05) .Conclusion Salinomycin prevents breast cancer cell transition from G1 to S phase through downregulation of the target genes of Hedgehog signaling pathway, leading to an effective inhibition of MDA-MB-231 cells.